drm/fourcc: fix Amlogic Video Framebuffer Compression macro

Fix the Amlogic Video Framebuffer Compression modifier macro to
correctly add the layout options, a pair of parenthesis was missing.

Fixes: d6528ec8 ("drm/fourcc: Add modifier definitions for describing Amlogic Video Framebuffer Compression")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200723090551.27529-1-narmstrong@baylibre.com