s390/char: Rename EBCDIC keymap variables

The Linux Virtual Terminal (VT) layer provides a default keymap
which is compiled when VT layer is enabled. But at the same time
we are also compiling the EBCDIC keymap and this causes the linker
to complain.

So let's rename the EBCDIC keymap variables to prevent linker
conflict.

Signed-off-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <f670a2698d2372e1e990c48a29334ffe894804b1.1519315352.git.alifm@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>