This patch adds the necessary MMU mappings for the Goya CPU to access the
device DRAM and the host memory.

The first 256MB of the device DRAM is being mapped. That's where the F/W
is running.

The 2MB area located on the host memory for the purpose of communication
between the driver and the device CPU is also being mapped.
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>