Just like was done with MM_REG_WRITE, remove the mask from the
MM_REG_POLL macro, leaving MM_REG_POLL_MASK to be used when a mask is
required, and update the call sites accordingly. In this case, all calls
require a mask, so MM_REG_POLL remains unused, but at least this makes
the MM_REG_POLL macros consistent with the MM_REG_WRITE ones.
Signed-off-by: Nícolas F. R. A. Prado <nfraprado@xxxxxxxxxxxxx>