regulator: arizona-ldo1: Add additional supported voltage

This patch adds support for the 1.175V mode on the LDO1 regulator on the
wm5110. This is need as part of the low power sleep mode operation.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>