ARM: dts: sunxi: Revert SRAM controller drivers patches

This patch reverts commit ccb4ada2 ("ARM: dts: sun7i: Add A20 SRAM and
SRAM controller"), commit e6f51e4b ("ARM: dts: sun5i: Add A13 and A10s
SRAM and SRAM controller") and commit 6d92b80f

 ("ARM: dts: sun4i: Add
A10 SRAM and SRAM controller").

The bindings have been changed in the SRAM driver, and we need to
change the DT accordingly.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>