Add a function to check whether there is at least one plane that
supports a specific format and modifier combination. Drivers can
use this to reject unsupported formats/modifiers in .fb_create().

v2: Accept anyformat if the driver doesn't do planes (Eric)
    s/planes_have_format/any_plane_has_format/ (Eric)
    Check the modifier as well since we already have a function
    that does both
v3: Don't do the check in the core since we may not know the
    modifier yet, instead export the function and let drivers
    call it themselves

Cc: Eric Anholt <eric@anholt.net>
Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181029183453.28541-1-ville.syrjala@linux.intel.com