ARM: zynq: Split slcr in two parts

Split the slcr into an early part for unlocking and cpu starting
and a later syscon driver.
Also add "syscon" compatible property for slcr.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/mach-zynq/common.h

@@ -20,6 +20,7 @@
 void zynq_secondary_startup(void);
 
 extern int zynq_slcr_init(void);
+extern int zynq_early_slcr_init(void);
 extern void zynq_slcr_system_reset(void);
 extern void zynq_slcr_cpu_stop(int cpu);
 extern void zynq_slcr_cpu_start(int cpu);