blackfin: Remove GENERIC_GPIO config option again

The Kconfig symbol GENERIC_GPIO was removed in v3.10. Nothing cares
about it anymore. It popped up somehow in v3.13, so it can be removed
again.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>

arch/blackfin/Kconfig

@@ -52,9 +52,6 @@ config GENERIC_BUG
 config ZONE_DMA
 	def_bool y
 
-config GENERIC_GPIO
-	def_bool y
-
 config FORCE_MAX_ZONEORDER
 	int
 	default "14"