msm: mdss: Remove HTC's PWM control type code

Nothing uses this stuff.

Change-Id: Ib3d36aa3cadc5b4eebea18e38e448ba33b3cc4ad
msm: mdss: Add back comments

Change-Id: Idf27305a863ae592113ab2c03e48219fea03c558
msm: mdss: Delete unreferenced files

Change-Id: I9cec2e556e29be2a171269755c92b74663dd5da8