pwm: qpnp: re-enable PWM or LUT output when configuration is changed

The PWM controller in Qualcomm PMIC chipset needs to re-enabled
if the underlying PWM configuration is changed. Currently all
the PWM client drivers are disabling pwm before changing configuration
and there is no output from PWM while changing the configuration.

Hence re-enable PWM or LUT output whenever the PWM or LUT
configuration is changed. This will allow clients to change
the configuration without first calling pwm_disable().

Change-Id: I3dd1b6644c2c04bdfb053ee7c6d18c59ae129295
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>