[binutils-gdb] POWER9 add scv/rfscv instruction support

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT dce75bf9848c88583377c608e9734a2f8616d12b ***

Author: Nicholas Piggin <npiggin@gmail.com>
Branch: master
Commit: dce75bf9848c88583377c608e9734a2f8616d12b

POWER9 add scv/rfscv instruction support

opcodes/
	* ppc-opc.c (powerpc_opcodes) <scv, rfscv>: New mnemonics.

gas/
	* testsuite/gas/ppc/power9.d <scv, rfscv>: New tests.