input: change mpu3050 driver to request regulator, add poll support

Needed on 8x30 MTP/MDP platforms, where interrupt line polled up and
does not work with driver's default configuration

Change-Id: I4827c7a1f7df147245336d18523088c013381f1e
Signed-off-by: Wentao Xu <wentaox@codeaurora.org>