Event Load Macro + GAS Tests Updated

	* gas/testsuite/gas/riscv/cv-elw-march-xcorev.d:
	  Upated instruction's encoding.
	* gas/testsuite/gas/riscv/cv-elw-pass.d: Updated
	  instruction's encoding.
	* include/opcode/riscv-opc.h: Updated MATCH_CV_ELW.

Signed-off-by: Nandni Jamnadas <nandni.jamnadas@embecosm.com>