cris: arch-v10: kgdb: Use BAR instead of DTP0 for register P12

For arch-v10, there is no DTP0 register, and at present, assembler know
BAR, so use BAR instead of DTP0, the related error (with allmodconfig):

    CC      arch/cris/arch-v10/kernel/kgdb.o
  {standard input}: Assembler messages:
  {standard input}:6: Error: Illegal operands
  {standard input}:6: Error: Illegal operands
Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Acked-by: Hans-Peter Nilsson <hp@axis.com>
Signed-off-by: Jesper Nilsson <jespern@axis.com>

arch/cris/arch-v10/kernel/kgdb.c

@@ -953,7 +953,7 @@ asm ("\n"
 "  move     $ibr,[cris_reg+0x4E]  ; P9,\n"
 "  move     $irp,[cris_reg+0x52]  ; P10,\n"
 "  move     $srp,[cris_reg+0x56]  ; P11,\n"
-"  move     $dtp0,[cris_reg+0x5A] ; P12, register BAR, assembler might not know BAR\n"
+"  move     $bar,[cris_reg+0x5A]  ; P12,\n"
 "                            ; P13, register DCCR already saved\n"
 ";; Due to the old assembler-versions BRP might not be recognized\n"
 "  .word 0xE670              ; move brp,r0\n"
@@ -1046,7 +1046,7 @@ asm ("\n"
 "  move     $ibr,[cris_reg+0x4E]  ; P9,\n"
 "  move     $irp,[cris_reg+0x52]  ; P10,\n"
 "  move     $srp,[cris_reg+0x56]  ; P11,\n"
-"  move     $dtp0,[cris_reg+0x5A] ; P12, register BAR, assembler might not know BAR\n"
+"  move     $bar,[cris_reg+0x5A]  ; P12,\n"
 "                            ; P13, register DCCR already saved\n"
 ";; Due to the old assembler-versions BRP might not be recognized\n"
 "  .word 0xE670              ; move brp,r0\n"