clk: sun6i: Protect SDRAM gating bit

Prevent the SDRAM controller from being gated by force-enabling it in the
machine code.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Emilio López <emilio@elopez.com.ar>

diff --cc drivers/clk/sunxi/clk-sunxi.c
Simple merge