Changed post inc instructions mnemonic

For issue [#101](https://github.com/openhwgroup/corev-binutils-gdb/issues/101

)

Files Changed:

  * opcodes/riscv-opc.c: Changed instruction mnemonic.
  * gas/testsuite/gas/riscv/cv-mem-fail-march.l: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-fail-march.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-fail-operand-01.l: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-fail-operand-01.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-fail-operand-02.l: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-fail-operand-02.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-fail-operand-03.l: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-fail-operand-03.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-fail-operand-04.l: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-fail-operand-04.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-fail-operand-05.l: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-fail-operand-05.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lbpost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lbpost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lbrrpost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lbrrpost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lbupost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lbupost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lburrpost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lburrpost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lhpost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lhpost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lhrrpost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lhrrpost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lhupost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lhupost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lhurrpost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lhurrpost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lwpost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lwpost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lwrrpost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-lwrrpost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-sbpost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-sbpost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-sbrrpost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-sbrrpost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-shpost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-shpost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-shrrpost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-shrrpost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-swpost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-swpost.s: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-swrrpost.d: Likewise.
  * gas/testsuite/gas/riscv/cv-mem-swrrpost.s: Likewise.

Signed-off-by: Mary Bennett <mary.bennett@embecosm.com>