regulator: arizona-ldo1: remove bypass functionality

WM5110/8280 devices do not support bypass mode for LDO1 so remove
the bypass callbacks registered with regulator core.

Signed-off-by: Nikesh Oswal <nikesh@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org