sf: virtual display clean up

  Since HAL allows Virtual devices, remove virtual display id
  check during setup of virtual display.

Change-Id: I6ec93c0f06842b69e6677f05ae8b45fb1f4225f6
Surface: Fix gralloc flags conflicting values.

Due to some custom code, unwanted flags (HW) got added with SW flags.
Restrict the flags to custom ones.

Change-Id: I2ab1c75eef4d6d16f0dd7d43aff3c7377486801a

Conflicts:
	libs/gui/Android.mk
frameworks/native: Reset update buffer geometry

Reset update buffer geometry when setBuffersGeometry is invoked to
reallocate the buffer for the new resolution.

Change-Id: I5da0bc8739af5e7c619ee6185b33712015112672
frameworks/native: fix copy back dirty region

Copyback dirty region logic does copyback,
even when its not necessary causing 2ms delay.
Fix the logic to copy back only what is necessary.

Change-Id: I52de68258ac9f87d704ee5401f93417805fa6773