egl/dri2: support for creating images out of dma buffers

egl/dri2: support for creating images out of dma buffers

v2:
   - upon success close the given file descriptors

v3:
   - use specific entry for dma buffers instead of the basic for
     primes, and enable the extension based on the availability
     of the hook

v4 (Chad):
   - use ARRAY_SIZE
   - improve the comment about the number of file descriptors
   - in case of invalid format report EGL_BAD_ATTRIBUTE instead
     of EGL_BAD_MATCH
   - take into account specific error set by the driver.

v5:
   - fix error handling

v6 (Chad):
   - fix invalid plane count checking

v7 (Chad):
   - fix indentation and reset loop counter before checking
     for excess attributes

Signed-off-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Reviewed-by: Chad Versace <chad.versace@linux.intel.com>