pmdomain: add audio power island for Marvell PXA1908 SoC

pmdomain: add audio power island for Marvell PXA1908 SoC

Define power domain which needs to be enabled in order for audio to work
on the PXA1908-based samsung,coreprimevelte smartphone. In the
downstream code, this power-on method is marked as specific to the ULCx
series which is allegedly a codename of sorts with ULC1 corresponding to
the PXA1908.

No other audio components needed for sound to work on this phone are
currently available mainline but some successful testing was performed
with the vendor variants of the respective drivers and with the domain
forced always-on.

Signed-off-by: Karel Balej <balejk@matfyz.cz>
Reviewed-by: Duje Mihanović <duje@dujemihanovic.xyz>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>