etna: more robust cmdbuffer flush handling

When something goes wrong during reserve, abort with an error, as it means
that the command buffer is in inconsistent state.

Also work around an apparent Vivante kernel driver bug that results in
hangs.
native: Remove symlinks.

 - Symlinks point to some local files, probably not needed.
 - Symlinks are breaking ptp-sync commit and disable synchronization feature.
add mth in to authors in README
README update
kernel_drivers: Add driver imported from Freescale BSP release 4.0.0.

Original source:
 - repository: git://git.freescale.com/imx/linux-2.6-imx.git
 - branch: imx_3.0.35_4.0.0
 - tag: rel_imx_3.0.35_4.0.0
 - commit id: 54750ff96a725ed78c057bc386d0f210c34bc53c

Driver tested with gpu-viv binary driver released by timesys:
 - gpu-viv-bin-mx6q-3.0.35-4.0.0.tar.gz
 - download link: http://repository.timesys.com/buildsources/g/gpu-viv-bin-mx6q/gpu-viv-bin-mx6q-3.0.35-4.0.0/gpu-viv-bin-mx6q-3.0.35-4.0.0.tar.gz
kernel_headers: Add headers imported from Freescale BSP release 4.0.0

Original source:
 - repository: git://git.freescale.com/imx/linux-2.6-imx.git
 - branch: imx_3.0.35_4.0.0
 - tag: rel_imx_3.0.35_4.0.0
 - commit id: 54750ff96a725ed78c057bc386d0f210c34bc53c

Driver tested with gpu-viv binary driver released by timesys:
 - gpu-viv-bin-mx6q-3.0.35-4.0.0.tar.gz
 - download link: http://repository.timesys.com/buildsources/g/gpu-viv-bin-mx6q/gpu-viv-bin-mx6q-3.0.35-4.0.0/gpu-viv-bin-mx6q-3.0.35-4.0.0.tar.gz
replay: Adjust Makefile for native/replay.
 - Remove repeated -lm flag (supplied by native/Makefile.inc).
 - Clean build products for GC800 and GC2000 on make clean.
egl: Fix build of egl demos with DIRECTFB.
 - Vivante headers require -DLINUX and -DEGL_API_DFB to determine that
   target system uses DIRECTFB.
 - Directfb headers are not in standard path.
 - Linking egl demos breaks without -ldl flag.
Add egl that only cleans screen.

Useful when looking into new chip.
Move ioctl structure definitions to gc_abi.h
Witch only one pipe PE_PIPE_DEPTH_ADDR[0]/PE_PIPE_COLOR_ADDR[0] are unused.
Merge pull request #8 from mike-sc/gc880

Gc880
driver: fix the build on !imx6_v4

gc_abi.h used `uint32_t` which was not yet defined there,
resulting in a compile error. Fix by simply using `unsigned int` as
that's what the kernel does too.
rnndb: add DMA debug register description

Info from imx6_v4_0_0 driver
driver: sanitize ETNA_PIPE usage to etna_pipe_context

We were abusing the priv field in struct pipe_context,
change this to use Mesa "inheritance" like for the other objects.
driver: compute component count for varyings

Find out which bits are used for PS inputs, and set the
varying configuration accordingly.
driver: remove newlines from DBG() messages
driver: implement clear_render_target, resource_copy_region and clear_depth_stencil

Implement clear_render_target, resource_copy_region and
clear_depth_stencil using Gallium blitter.
tools: add i.mx6 duallite to gpus comparison
driver: fix scissors

Scissor bottom state was set wrongly, resulting in wild and various
problems from display corruption to crashes when scissor was enabled.