ASoC: bcm2835-i2s: Use maple tree register cache

The bcm2835 I2S driver uses a rbtree register cache but has no clear need
to do so. Since the maple tree cache uses a more modern data structure and
makes implementation decisions more suitable for current systems switch the
driver to use that instead. No functional changes.

Signed-off-by: Mark Brown <broonie@kernel.org>
1 file changed