When building only G12A, ensure that VID_PLL_DIV clock driver is
selected, otherwise results in this build error:

ERROR: modpost: "meson_vid_pll_div_ro_ops" [drivers/clk/meson/g12a.ko] undefined!

Fixes: 085a4ea9 ("clk: meson: g12a: add peripheral clock controller")
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20201118190930.34352-1-khilman@baylibre.com