stagefright: update support for omap3 decoders and encoders

OMAP3 uses 2 decoders, 720P.Decoder and Video.Decoder.

720P.Decoder is proprietary OMAP3 decoder from ITTIAM. Only
one instance of the 720P decoder can run at a time due to memory
restrictions (512MB) and it's quite slow at thumbnail generation
and it's resource hungry.

Video.Decoder is opensource and could support WVGA resolutions.
It only supports baseline profile and max level 31 for AVC, but
could run 4 instances at the same time and is quite fast especially
for watching WhatsApp videos :P

Using the 720P decoder for low resolution videos is not optimal and
trying to use the Video.Decoder for videos other than Baseline profile
will crash the entire DSP and would require a reboot. Currently
stagefright uses codecs in the order they appear in media_codecs.xml
without querying the supported level and profile from the decoder,
due to which wrong codecs are selected causing problems.

Similarly there are 2 encoders, 720P.Encoder and Video.Encoder. They
support different resolutions and should be used selectively.

This patch has been forward ported from Gingerbread branch.

Change-Id: I74f843fe5d28faefa0b51191778ab2ee8c54f5f6