ARM: spear3xx_defconfig: Activate PL111 DRM driver

This disables the old FBDEV driver and enables the PL111
DRM driver on the SPEAr3xx.

There are some device trees in the kernel that switches
the DT node for the PL110 to "okay" but none of these
have any display defined, so we can safely switch to this
driver before we get any users starting to define
displays. Let them do it on top of the new driver
infrastructure instead.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>