ARM: imx27: Retrieve the SYSCTRL base address from devicetree

[ Upstream commit 94b2bec1b0e054b27b0a0b5f52a0cd55c83340f4 ]

Now that imx27 has been converted to a devicetree-only platform,
retrieve the SYSCTRL base address from devicetree.

To keep devicetree compatibilty the SYSCTRL base address will be
retrieved from the CCM base address plus an 0x800 offset.

This is not a problem as the imx27.dtsi describes the CCM register
range as 0x1000.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Stable-dep-of: 87b30c4b0efb ("ARM: imx: add missing of_node_put()")
Signed-off-by: Sasha Levin <sashal@kernel.org>