Revert "BACKPORT: FROMLIST: pwm: Add support for different PWM output types"

This reverts commit 106a4b85.

This is a failed upstream attempt.  The patch itself is 3.5 years old
and the last known upstream submission was over 18 months ago, which
was NACK'ed.  The code also appears to be unused.

Suggested-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Change-Id: I8e56b2557e47b1a5a5323ec04d1071fae85ecb4b