ARM: mach-imx: imx6ul: Print SOC revision on boot

Add the print of the CPU type and SOC revision during boot.

Signed-off-by: Stefan Riedmueller <s.riedmueller@phytec.de>
Signed-off-by: Robert Karszniewicz <r.karszniewicz@phytec.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>