Flip CONFIG_SND_SOC_CS35L56_SDW to m and clean up

Upstream commit 4754e29c makes SND_SOC_INTEL_SOUNDWIRE_SOF_MACH select SND_SOC_CS35L56. This was previously disabled in RHEL and the new select results in a mismatch. Let's turn on CONFIG_SND_SOC_CS35L56_SDW for x86 in common, and lean up all of the other references to it.

Signed-off-by: Justin M. Forbes jforbes@fedoraproject.org