[opcodes] Use 0xC1 for "isa_config" aux reg

[shahab-vahedi]

The arc-regs.h suggests that for the build config register in arc600 family, value 0xc1 is used. However, the ARC_OPCODE_ALL (?) must use 0xc2.

DEF (0xc1,  ARC_OPCODE_ARC600,  NONE, arc600_build_config)
DEF (0xc2,  ARC_OPCODE_ARCALL,  NONE, isa_config)

This is not correct, as checking against mwdt reveals.

$ cat isa_config.S
   lr r0, [isa_config]

---------------------- [ arcv2 built by mwdt ]------------------------

$ asac -arcv2hs isa_config.S -o isa_config.o
  MetaWare ELF Dumper ENG-2020.09-007 (build TIP-24-Jul-2020)

$ elfdump -T isa_config.o
  Dump of "isa_config.o":
  Content of section .text (#1) size=0x4 start=0x34
     0: 20aa0043                 lr       %r0,[%isa_config]

$ arc-elf32-objdump -dr isa_config.o
  isa_config.o:     file format elf32-littlearc
  Disassembly of section .text:
  00000000 <$t>:
     0:   20aa 0043               lr      r0,[193]     # 0xc1

---------------------- [ arc600 built by mwdt ]-----------------------

$ asac -arc600 isa_config.S -o isa_config.o
  MetaWare ARC Assembler ENG-2020.09-007 (build TIP-24-Jul-2020)
  "isa_config.S",Line 1: warning (#113) Register isa_config is not
  supported in the ARC600 processor family

$ elfdump -T isa_config.o
  Dump of "isa_config.o":
  Content of section .text (#1) size=0x4 start=0x34
     0: 20aa0043                 lr       %r0,[%arc600_build_config]

$ arc-elf32-objdump -dr isa_config.o
  isa_config.o:     file format elf32-littlearc
  Disassembly of section .text:
  00000000 <$t>:
     0:   20aa 0043               lr      r0,[193]     # 0xc1

---------------------- [ arcv2 built by gnu ]-------------------------

$ arc-elf32-gcc -mcpu=archs -c isa_config.S -o isa_config.o

$ elfdump -T isa_config.o
  Dump of "isa_config.o":
  Content of section .text (#1) size=0x4 start=0x34
     0: 20aa0083                 lr       %r0,[0xc2]

$ arc-elf32-objdump -dr isa_config.o
  isa_config.o:     file format elf32-littlearc
  Disassembly of section .text:
  00000000 <$t>:
     0:   20aa 0083               lr      r0,[isa_config]

---------------------- [ arc600 built by gnu ]------------------------

$ arc-elf32-gcc -mcpu=arc600 -c isa_config.S -o isa_config.o

$ elfdump -T isa_config.o
  Dump of "isa_config.o":
  Content of section .text (#1) size=0x4 start=0x34
     0: 20aa0083                 lr       %r0,[0xc2]

$ arc-elf32-objdump -dr isa_config.o
  isa_config.o:     file format elf32-littlearc
  Disassembly of section .text:
  00000000 <$t>:
     0:   20aa 0083               lr      r0,[isa_config]

----------------------------------------------------------------------

[shahab-vahedi]

Fixed in arc: Fix the address for "isa_config" aux reg.