[ARM] pxa: simplify the LCD pin configuration for pxa25x platforms

There are only limited possible LCD pin configurations for pxa25x
platforms, simplify this by macro.

Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
diff --git a/arch/arm/mach-pxa/cm-x255.c b/arch/arm/mach-pxa/cm-x255.c
index 253fd76..f1a7703 100644
--- a/arch/arm/mach-pxa/cm-x255.c
+++ b/arch/arm/mach-pxa/cm-x255.c
@@ -50,26 +50,7 @@
 	GPIO47_STUART_TXD,
 
 	/* LCD */
-	GPIO58_LCD_LDD_0,
-	GPIO59_LCD_LDD_1,
-	GPIO60_LCD_LDD_2,
-	GPIO61_LCD_LDD_3,
-	GPIO62_LCD_LDD_4,
-	GPIO63_LCD_LDD_5,
-	GPIO64_LCD_LDD_6,
-	GPIO65_LCD_LDD_7,
-	GPIO66_LCD_LDD_8,
-	GPIO67_LCD_LDD_9,
-	GPIO68_LCD_LDD_10,
-	GPIO69_LCD_LDD_11,
-	GPIO70_LCD_LDD_12,
-	GPIO71_LCD_LDD_13,
-	GPIO72_LCD_LDD_14,
-	GPIO73_LCD_LDD_15,
-	GPIO74_LCD_FCLK,
-	GPIO75_LCD_LCLK,
-	GPIO76_LCD_PCLK,
-	GPIO77_LCD_BIAS,
+	GPIOxx_LCD_TFT_16BPP,
 
 	/* SSP1 */
 	GPIO23_SSP1_SCLK,