drm/tidss: dispc: Convert accessors to macros

drm/tidss: dispc: Convert accessors to macros

The dispc driver uses upper-cased, inlined, functions to provide
macro-like accessors to the dispc registers.

This is confusing, since upper-case is usually used by macros, and that
pattern will create gcc errors later on in this series.

Let's switch to macros to make it more consistent, and prevent those
errors down the line.

Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20250827-drm-tidss-field-api-v3-2-7689b664cc63@kernel.org
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>