egl_dri2: Remove depth argument from dri2_add_config()
All callers now use the more correct rgba mask mechanism for filtering
out mathcing DRI configs. Even if depth and buffer size match, the
color component layout can be different, or in case or ARGB8888 and
ARGB2101010 the color components can even be different sizes.
Since anything that the depth check would reject is also rejected by
the rgba mask comparison, the depth parameter is redundant and not
specific enough. We should probably have removed it when the rgba
masks argument was introduced, but better late than never.
Signed-off-by: Kristian Høgsberg <krh@bitplanet.net>