hexdump: more output formatting

Add a prefix string parameter.  Callers are responsible for any string
length/alignment that they want to see in the output.  I.e., callers should
pad strings to achieve alignment if they want that.

Add rowsize parameter.  This is the number of raw data bytes to be printed
per line.  Must be 16 or 32.

Add a groupsize parameter.  This allows callers to dump values as 1-byte,
2-byte, 4-byte, or 8-byte numbers.  Default is 1-byte numbers.  If the
total length is not an even multiple of groupsize, 1-byte numbers are
printed.

Add an "ascii" output parameter.  This causes ASCII data output following
the hex data output.

Clean up some doc examples.

Align the ASCII output on all lines that are produced by one call.

Add a new interface, print_hex_dump_bytes(), that is a shortcut to
print_hex_dump(), using default parameter values to print 16 bytes in
byte-size chunks of hex + ASCII output, using printk level KERN_DEBUG.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>