MIPS: PowerTV: Add Gaia platform definitions.

Define ASIC address, memory preallocations, and initialization code for the
Gaia platform.

Signed-off-by: David VomLehn <dvomlehn@cisco.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1519/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>