openrisc: Pretty print show_registers memory dumps

Currently show registers, print memory dumps character by character and
there is no address information, so its a bit difficult to use.  For
example before a stack dump looks as follows.

    [   13.650000] Stack:
    [   13.650000] Call trace
    [   13.690000] [<(ptrval)>] ? put_timespec64+0x44/0x60
    [   13.690000] [<(ptrval)>] ? _data_page_fault_handler+0x104/0x10c
    [   13.700000]
    [   13.700000] Code:
    [   13.700000] 13
    [   13.700000] ff
    [   13.700000] ff
    [   13.700000] f9
    [   13.710000] 84
    [   13.710000] 82
    [   13.710000] ff
    [   13.710000] bc
    [   13.710000] 07
    [   13.710000] fd
    [   13.720000] 4e
    [   13.720000] 67
    [   13.720000] 84
    [   13.720000] 62
    [   13.720000] ff
    ...

This change updates this to print the address and data a word at time.

    [    0.830000] Stack:
    [    0.830000] Call trace:
    [    0.830000] [<(ptrval)>] load_elf_binary+0x744/0xf5c
    [    0.830000] [<(ptrval)>] ? __kernel_read+0x144/0x184
    [    0.830000] [<(ptrval)>] bprm_execve+0x27c/0x3e4
    [    0.830000] [<(ptrval)>] kernel_execve+0x16c/0x1a0
    [    0.830000] [<(ptrval)>] run_init_process+0xa0/0xec
    [    0.830000] [<(ptrval)>] ? kernel_init+0x0/0x14c
    [    0.830000] [<(ptrval)>] kernel_init+0x7c/0x14c
    [    0.830000] [<(ptrval)>] ? calculate_sigpending+0x30/0x40
    [    0.830000] [<(ptrval)>] ret_from_fork+0x1c/0x84
    [    0.830000]
    [    0.830000]  c1033dbc:       c1033dec
    [    0.830000]  c1033dc0:       c015258c
    [    0.830000]  c1033dc4:       c129da00
    [    0.830000]  c1033dc8:       00000002
    [    0.830000]  c1033dcc:       00000000
    [    0.830000]  c1033dd0:       c129da00
    [    0.830000]  c1033dd4:       00000000
    [    0.830000]  c1033dd8:       00000000
    [    0.830000] (c1033ddc:)      00001e04
    [    0.830000]  c1033de0:       001501fc
    [    0.830000]  c1033de4:       c1033e68
    [    0.830000]  c1033de8:       c0152e60
    [    0.830000]  c1033dec:       c129da5c
    [    0.830000]  c1033df0:       c0674a20
    [    0.830000]  c1033df4:       c1033e50
    [    0.830000]  c1033df8:       c00e3d6c
    [    0.830000]  c1033dfc:       c129da5c
    [    0.830000]  c1033e00:       00000003
    [    0.830000]  c1033e04:       00150000
    [    0.830000]  c1033e08:       00002034
    [    0.830000]  c1033e0c:       001501fc
    [    0.830000]  c1033e10:       00000000
    [    0.830000]  c1033e14:       00150000
    [    0.830000]  c1033e18:       0014ebbc
    [    0.830000]  c1033e1c:       00002000
    [    0.830000]  c1033e20:       00000003
    [    0.830000]  c1033e24:       c12a07e0
    [    0.830000]  c1033e28:       00000000
    [    0.830000]  c1033e2c:       00000000
    [    0.830000]  c1033e30:       00000000
    [    0.830000]  c1033e34:       40040000
    [    0.830000]  c1033e38:       00000000
    [    0.830000]
    [    0.830000] Code:
    [    0.830000]  c00047a4:       9c21fff8
    [    0.830000]  c00047a8:       d4012000
    [    0.830000]  c00047ac:       d4011804
    [    0.830000]  c00047b0:       e4040000
    [    0.830000]  c00047b4:       10000005
    [    0.830000]  c00047b8:       9c84ffff
    [    0.830000] (c00047bc:)      d8030000
    [    0.830000]  c00047c0:       03fffffc
    [    0.830000]  c00047c4:       9c630001
    [    0.830000]  c00047c8:       9d640001
    [    0.830000]  c00047cc:       84810000
    [    0.830000]  c00047d0:       84610004

Now we are also printing a bit of the stack as well as the code.  The
stack is output to help with debugging.  There may be concern about
exposing sensitive information on the stack, but we are already dumping
all register content which would have similar sensitive information.  So
I am going ahead as this proves useful in investigation.

Signed-off-by: Stafford Horne <shorne@gmail.com>