ARM: dts: gemini: Re-enable display controller

commit 137cd710
"ARM: dts: Enable Gemini flash access" contained a bug
by disabling the display controller, while the whole
idea with the patch was to enable flash access AND
the display controller, simultaneously. Fix it up.

Fixes: 137cd710

 ("ARM: dts: Enable Gemini flash access")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>