arm: omap2plus: move NAND_BLOCK_SIZE out of boards

Several boards defining mtd partitions also defined NAND_BLOCK_SIZE as
SZ_128K. Move the define to common-board-devices.h

This removes multiple defines of NAND_BLOCK_SIZE.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
[tony@atomide.com: updated comments]
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap2/board-cm-t3517.c b/arch/arm/mach-omap2/board-cm-t3517.c
index 30e9c6bb..c3a9fd3 100644
--- a/arch/arm/mach-omap2/board-cm-t3517.c
+++ b/arch/arm/mach-omap2/board-cm-t3517.c
@@ -48,6 +48,7 @@
 
 #include "mux.h"
 #include "control.h"
+#include "common-board-devices.h"
 
 #if defined(CONFIG_LEDS_GPIO) || defined(CONFIG_LEDS_GPIO_MODULE)
 static struct gpio_led cm_t3517_leds[] = {
@@ -203,8 +204,6 @@
 #endif
 
 #if defined(CONFIG_MTD_NAND_OMAP2) || defined(CONFIG_MTD_NAND_OMAP2_MODULE)
-#define NAND_BLOCK_SIZE		SZ_128K
-
 static struct mtd_partition cm_t3517_nand_partitions[] = {
 	{
 		.name           = "xloader",