ASoC: rsnd: clear SSI_SYS_STATUSx every time

Renesas sound SSIU has SSI_SYS_STATUS register whick will
be changed if over/under run was occurred.
Current rsnd driver is handling over/under run error on SSI/SRC,
but doesn't on SSIU.
HW guys can't guarantee correct behavior if it already had error bit
on status register when it start.
Thus, it should be cleared every start timing. This patch do it.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>