omap2: nand: Make NAND_OMAP_GPMC_PREFETCH default

This option provides better performance and should really always be
enabled.  Make this be default y.

Signed-off-by: Tom Rini <trini@konsulko.com>
Acked-by: Jeroen Hofstee <jeroen@myspectrum.nl>

drivers/mtd/nand/Kconfig

@@ -55,6 +55,7 @@ config NAND_OMAP_GPMC
 config NAND_OMAP_GPMC_PREFETCH
 	bool "Enable GPMC Prefetch"
 	depends on NAND_OMAP_GPMC
+	default y
 	help
 	  On OMAP platforms that use the GPMC controller
 	  (CONFIG_NAND_OMAP_GPMC_PREFETCH), this options enables the code that