ARM: omap: fix warning with LPAE build

Some omap3 code is throwing a warning:
arch/arm/mach-omap2/pm34xx.c: In function 'omap3_save_secure_ram_context':
arch/arm/mach-omap2/pm34xx.c:123:32: warning: cast to pointer from
  integer of different size [-Wint-to-pointer-cast]

In reality this code will never actually execute with LPAE=y, since
Cortex-A8 doesn't support it. So downcasting the __pa() is safe in
this case.
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/pm34xx.c

@@ -120,7 +120,7 @@ static void omap3_save_secure_ram_context(void)
 		 * will hang the system.
 		 */
 		pwrdm_set_next_pwrst(mpu_pwrdm, PWRDM_POWER_ON);
-		ret = _omap_save_secure_sram((u32 *)
+		ret = _omap_save_secure_sram((u32 *)(unsigned long)
 				__pa(omap3_secure_ram_storage));
 		pwrdm_set_next_pwrst(mpu_pwrdm, mpu_next_state);
 		/* Following is for error tracking, it should not happen */