Fixes for mic and A/V issues on capri based devices

[PATCH 1/2] OMXCodec: set default input buffer size

Broadcom OMX only set the buffer size to 65536 by default which
is not enough for higher bitrate video

[PATCH 2/2] OMXCodec: set default input buffer size only for BCM
decoder

Needed for capri based i9082 device .

Change-Id: Iee5d02829da46f91a326c0fab3e60996af55a1f9