ARM: 6637/1: Make the argument to virt_to_phys() "const volatile"

Changing the virt_to_phys() argument to "const volatile void *" avoids
compiler warnings in some situations where this function is used.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/memory.h

@@ -188,7 +188,7 @@
  * translation for translating DMA addresses.  Use the driver
  * DMA support - see dma-mapping.h.
  */
-static inline unsigned long virt_to_phys(void *x)
+static inline unsigned long virt_to_phys(const volatile void *x)
 {
 	return __virt_to_phys((unsigned long)(x));
 }