ASoC: rsrc-card: rename rsrc-card to simple-scu-card phase1

ASoC: rsrc-card: rename rsrc-card to simple-scu-card phase1

rsrc-card which is using DPCM feature was created for Renesas sound.
But not only Renesas, but many SoC can use this driver, because
it is based on simple-card driver.
To use it as more open driver, rsrc-card will be renamed to
simple-scu-card. In order to easy patch review, as 1st step,
this patch renames "rsrc" function prefix to "asoc_simple".

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