add new registers:
	mmSDMA0_RLC3_RB_WPTR_POLL_CNTL,
	mmSDMA1_RLC3_RB_WPTR_POLL_CNTL
Reviewed-by: Xiaojie Yuan <xiaojie.yuan@amd.com>
Signed-off-by: tiancyin <tianci.yin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>