ANDROID: GKI: pwm: Add different PWM output types support

Normally, PWM channel has fixed output until software request to change
its settings. There are some PWM devices which their outputs could be
changed autonomously according to a predefined pattern programmed in
hardware. Add pwm_output_type enum type to identify these two different
PWM types and add relevant helper functions to set and get PWM output
types and pattern.

Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>
Bug: 152542675
Test: build and boot
(cherry picked from commit 9e880ec7)
[surenb: removed sysfs changes and fixed checkpatch.pl error in
pwm_get_output_type_supported function from pwm.h]
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: I4a457636547e3225d8f10cfb3237765f500d9cc7
Merged-In: I4a457636547e3225d8f10cfb3237765f500d9cc7