drm: probe_helper: Hide ugly ifdef

Push the ifdef to the drm_edid.h and create a stub, for the
DRM_LOAD_EDID_FIRMWARE=n case. This removes some clutter in
the code, making it more readable.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461087638-16959-1-git-send-email-ezequiel@vanguardiasur.com.ar
Git-commit: ba34d58c5e86c27accb3133fa991cfb6c848c58e
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Change-Id: Ice586a7d90538d77a3f120bb9ba6214e17b926d0
Signed-off-by: Tanmay Shah <tanmay@codeaurora.org>