display: Add option to disable hardware VSYNC

 * Set TARGET_NO_HW_VSYNC to disable use of VSYNC

Adapted from jellybean (was Change-Id: I9c48f89ba6d4a39baf7c149717b13c83c0b7f3eb)
Signed-off-by: Michael Bestas <mikeioannina@gmail.com>

Change-Id: I5d38a1004cd0fd9931eda471937c6f827d9de1bc