ASoC: rsnd: add generic rsnd_flags_xxx() macro

SSI is using rsnd_ssi_flags_xxx() macro to control flags.
But it is useful macro not only for SSI. This patch replace it
to more generic rsnd_flags_xxx().

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