EXYNOS5: Make all display related code dependent on CONFIG_LCD

u-boot compilation fails for smdk5250 when we deselect CONFIG_LCD
from the main config file.

Following error was observed:
drivers/video/libvideo.o: In function `exynos_lcd_init':
/home/ajay/u-boot-samsung/drivers/video/exynos_fb.c:68: undefined reference to `lcd_set_flush_dcache'

This is because exynos video drivers have dependency on CONFIG_LCD.

Signed-off-by: Ajay Kumar <ajaykumar.rs@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

board/samsung/smdk5250/smdk5250.c

@@ -281,6 +281,7 @@ int board_early_init_f(void)
 }
 #endif
 
+#ifdef CONFIG_LCD
 void cfg_lcd_gpio(void)
 {
 	struct exynos5_gpio_part1 *gpio1 =
@@ -374,3 +375,4 @@ void init_panel_info(vidinfo_t *vid)
 
 	exynos_set_dp_platform_data(&dp_platform_data);
 }
+#endif

include/configs/exynos5250-dt.h

@@ -299,10 +299,12 @@
 
 /* Display */
 #define CONFIG_LCD
+#ifdef CONFIG_LCD
 #define CONFIG_EXYNOS_FB
 #define CONFIG_EXYNOS_DP
 #define LCD_XRES			2560
 #define LCD_YRES			1600
 #define LCD_BPP			LCD_COLOR16
+#endif
 
 #endif	/* __CONFIG_H */