drm/sun4i: Fix macros in sun8i_csc.h

Macros SUN8I_CSC_CTRL() and SUN8I_CSC_COEFF() don't follow usual
recommendation of having arguments enclosed in parenthesis. While that
didn't change anything for quite sometime, it actually become important
after CSC code rework with commit ea067aee ("drm/sun4i: de2/de3:
Remove redundant CSC matrices").

Without this fix, colours are completely off for supported YVU formats
on SoCs with DE2 (A64, H3, R40, etc.).

Fix the issue by enclosing macro arguments in parenthesis.

Cc: stable@vger.kernel.org # 5.12+
Fixes: 88302939 ("drm/sun4i: Add DE2 CSC library")
Reported-by: Roman Stratiienko <r.stratiienko@gmail.com>
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20210831184819.93670-1-jernej.skrabec@gmail.com