fsm: Enable UIM interface

FSM9XXX UART3 has a UIM interface. UART3 device is designated to UIM,
and GPIOs and PMIC are configured to bring up UIM interface.

Change-Id: Iac6f633f1051a93a92f6c6b3e5dff2c869fcd209
Acked-by: Ho Lee <holee@qualcomm.com>
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>