Add support for Xperia Play touchpads

Original implementation by farenheith@xda.
http://forum.xda-developers.com/showthread.php?t=1893343

Signed-off-by: Michael Bestas <mikeioannina@gmail.com>

Change-Id: I26c7d3f4ff6f0043a45d9ebdc3fa7cc29f06ef9d
Lower the RAM requirement for hardware acceleration

There are legacy devices with about 365 MBytes of RAM
available to the kernel (HDPI with 512 MB RAM onboard).
Lowering the requirement value for available RAM allows
these devices to also use hardware acceleration, thus
making the UI a lot more responsive and fixing bugs like
this: https://dl.dropboxusercontent.com/u/16268774/Screenshots/Phone/Screenshot_2013-10-07-01-27-45.png
(notice the "shadow" is missing)

Change-Id: I0343ddbb3c7f95bed674b5852772ab819065ea69