platform: msm: Update QPNP-PWM driver to correct PWM output configuration

In the ENABLE_CONTROL LPG SPMI-regiser, "EN_PWM_OUTPUT" controls
only the tri-stated output. This output gets connected
to MPPs. It has nothing to do with the actual PWM output.
The actual PWM output is controlled by "EN_PWM_HI" and
"EN_PWM_LO" bits. Update the qpnp-pwm driver to reflect
these changes.

Change-Id: I4801b9b2013f54b3682be02d1cfbedc5e644e276
Signed-off-by: Jay Chokshi <jchokshi@codeaurora.org>