hwc: Disable fake vsync

Disable fall back to fake vsync even when the vsync timestamp is
invalid.

Related-to-bug: 8804359
Change-Id: Ia8fba19ce1bd0635985c6414bbcbd97b76054ebf
Signed-off-by: Iliyan Malchev <malchev@google.com>
hwc: Make sure vsync is enabled after unblank

Make sure the unblank call is completed before vsync is enabled.

Related-to-bug: 8804359
Change-Id: I18e4c3e6c3942cd325e85d99859135562748b0c4
Signed-off-by: Iliyan Malchev <malchev@google.com>

Conflicts:
	libhwcomposer/hwc.cpp
hwc: Do not close fd when vsync read fails

Related-to-bug: 8804359
Change-Id: I7495c03910a57c2e2090fac6d7ba203de556a0b1
Signed-off-by: Iliyan Malchev <malchev@google.com>
hwc: Simplify vsync code

Handle the wait properly in the kernel and remove unnecessary
thread signaling.

Change-Id: Iff05825a7a85d0353f3feb64e7f9a06cedab7869

Conflicts:
	libhwcomposer/hwc_utils.cpp
	libhwcomposer/hwc_vsync.cpp