ASoC: rsnd: open 31bit of SSICKR mask

SSICKR (Gen2) / BRGCKR (Gen3) 31bit mask should be opened,
because BRGB (= for 48kHz) might select it.
Special thanks Yokoyama-san

Reported-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>