gpu: vivante: Initial import of GC860 Vivante kernel side driver.

Initial import of Vivante GPU code version 2.5.3.2.5.b7 for Ingenic
JZ4770 SoC with Vivante GC860 VPU. The copyright headers were updated
to be GPL again, since the previous 2.5.3.2.5.x releases had it and
then they were accidentally changed due to auto-generation of files.
Updated the date to be 2012.

Signed-off-by: Steven J. Hill <sjhill@realitydiluted.com>
gpu: vivante: Apply latest Ingenic patch to Vivante driver.

This was the last support patch from Vivante to Ingenic that the
GCW-Zero team received.

Signed-off-by: Steven J. Hill <sjhill@realitydiluted.com>
gpu: vivante: Make Vivante driver buildable on GCW0.

Make changes necessary in order to build the the GC860 driver for
the JZ4770 platforms:

* All instances of CONFIG_SOC_JZ4770 were changed to CONFIG_MACH_JZ4770
  which is a more standard naming.
* The VM_RESERVED flag is no longer used in 3.7 and newer kernels. The
  flag is replaced by either VM_IO or (VM_DONTEXPAND | VM_DONTDUMP) in
  newer kernels. Since VM_IO was already there, it made sense just to
  replace VM_RESERVED with VM_DONTDUMP flag for completeness. Maybe in
  the future just VM_IO can be used.
* The 'do_mmap_pgoff' and 'do_munmap' functions in 'mm/mmap.c' were
  being used by the driver. These do not get exported to kernel modules,
  so new functions 'plat_do_mmap_pgoff' and 'plat_do_munmap' were
  created and exported. They are simple wrapper functions that pass the
  arguments straight to the corresponding 'mm/mmap.c' functions.
* Added '-Wframe-larger-than=1032' to EXTRA_CFLAGS to silence warning.
* Fixed a string format warning.

Signed-off-by: Steven J. Hill <sjhill@realitydiluted.com>
gpu: vivante: Make the GC860 selectable.

Add the Vivante GC860 driver to the config and build system so
that the user can select and build it. The configuration file
has also been updated.

Signed-off-by: Steven J. Hill <sjhill@realitydiluted.com>