isa1200: Add support for pwm clk

PWM generation mode needs clk to generate internal PWM
for vibration. Add clk apis to enable/disable clock as
needed.

Change-Id: I2ba591509fc899186bf0ad7069133a9f1d0e6a42
Signed-off-by: Mohan Pallaka <mpallaka@codeaurora.org>
3 files changed