libstagefright: Add support for the 720P OMAP3 encoders

Bring back some more OMAP code that was removed by Google in JB,
and a couple of omapzoom patches.
This may stop being necessary if TI publishes JB-specific OMAP3
code, but as long as we're using the ICS domx, these need to
be here
Change-Id: Ia29f8c9f9ed769ba07b09c07260486f6502841d6