egl: android: add dma-buf fd support

egl: android: add dma-buf fd support

Add support for creating images from Android native buffers with dma-buf
fd. As dma-buf support also requires DRI image loader extension, add
that as well.

This is based on several originally patches written by Varad Gautam.
I've collapsed them into logical changes and done a bit of reformatting.
Using dma-bufs vs. GEM handles is now a runtime decision similar to the
wayland EGL instead of being compile time selection. The dma-buf support
is also re-written to use common dri2_create_image_dma_buf function in
egl_dri2.c.

Cc: Varad Gautam <varadgautam@gmail.com>
Cc: Rob Clark <robdclark@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>