ARM: OMAP2: Fix section warning for n8x0 when CONFIG_MMC_OMAP is not set

Otherwise we get:

arch/arm/mach-omap2/board-n8x0.c:39:12: warning:
'slot1_cover_open' defined but not used [-Wunused-variable]
arch/arm/mach-omap2/board-n8x0.c:40:12: warning:
'slot2_cover_open' defined but not used [-Wunused-variable]
arch/arm/mach-omap2/board-n8x0.c:41:23: warning:
'mmc_device' defined but not used [-Wunused-variable]
Reported-by: NRussell King <linux@arm.linux.org.uk>
Signed-off-by: NTony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/board-n8x0.c

@@ -36,10 +36,6 @@
 
 #include "mux.h"
 
-static int slot1_cover_open;
-static int slot2_cover_open;
-static struct device *mmc_device;
-
 #define TUSB6010_ASYNC_CS	1
 #define TUSB6010_SYNC_CS	4
 #define TUSB6010_GPIO_INT	58
@@ -211,6 +207,10 @@ static struct omap_onenand_platform_data board_onenand_data[] = {
 #define N810_EMMC_VSD_GPIO	23
 #define N810_EMMC_VIO_GPIO	9
 
+static int slot1_cover_open;
+static int slot2_cover_open;
+static struct device *mmc_device;
+
 static int n8x0_mmc_switch_slot(struct device *dev, int slot)
 {
 #ifdef CONFIG_MMC_DEBUG