Add multiple instance direct SRAM read and write support for vcn2.5

v2: squash in indexing fix
Signed-off-by: NJames Zhu <James.Zhu@amd.com>
Reviewed-by: NLeo Liu <leo.liu@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>