Removed obsolete MAC instructions

gas/testsuite/ChangeLog.COREV:

	* gas/riscv/cv-mac-machhsn.d: Removed obsolete instruction cv.machhs.
	* gas/riscv/cv-mac-machhun.d: Removed obsolete instruction cv.machhu.
	* gas/riscv/cv-mac-macsn.d: Removed obsolete instruction cv.macs.
	* gas/riscv/cv-mac-macun.d: Removed obsolete instruction cv.macu.

include/ChangeLog.COREV:

	* opcode/riscv-opc.h: Removed obsolete matches and renamed mask
	accordingly -
	MATCH_MACS:	Removed.
	MATCH_MACHHS:	Removed.
	MATCH_MACU:	Removed.
	MATCH_MACHHU:	Removed.
	MASK_MULMAC ->	MASK_MULSH

opcodes/ChangeLog.COREV:

	* riscv-opc.c: Removed obsolete instructions -
	cv.macs:	Removed.
	cv.machhs:	Removed.
	cv.macu:	Removed.
	cv.machhu:	Removed.

Signed-off-by: Jessica Mills <jessica.mills@embecosm.com>