Add a "do you support this modifier?" query to all
drivers which support format modifiers. This will
be used in a subsequent change to fully
encapsulate modifier validation and auxiliary plane
count calculation logic behind the driver
abstraction, which will in turn simplify the
addition of device-class-specific format modifiers
in the nouveau driver.

Signed-off-by: James Jones <jajones@nvidia.com>
Part-of: <!3723>