ARM: move CP15 definitions to separate header file

Avoid namespace conflicts with drivers over the CP15 definitions by
moving CP15 related prototypes and definitions to a private header
file.

Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com> [Tegra]
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com> [EP93xx]
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/arch/arm/mach-vexpress/hotplug.c b/arch/arm/mach-vexpress/hotplug.c
index 3034a4d..c504a72 100644
--- a/arch/arm/mach-vexpress/hotplug.c
+++ b/arch/arm/mach-vexpress/hotplug.c
@@ -14,7 +14,7 @@
 
 #include <asm/cacheflush.h>
 #include <asm/smp_plat.h>
-#include <asm/system.h>
+#include <asm/cp15.h>
 
 extern volatile int pen_release;