Blackfin arch: convert BF5{18,27,48}_FAMILY to CONFIG_BF{51,52,54}x

convert BF5{18,27,48}_FAMILY to CONFIG_BF{51,52,54}x as the defines
are redundant in these cases

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

diff --git a/arch/blackfin/include/asm/gpio.h b/arch/blackfin/include/asm/gpio.h
index 3c99ddc..fe13961 100644
--- a/arch/blackfin/include/asm/gpio.h
+++ b/arch/blackfin/include/asm/gpio.h
@@ -110,7 +110,7 @@
 * MODIFICATION HISTORY :
 **************************************************************/
 
-#ifndef BF548_FAMILY
+#ifndef CONFIG_BF54x
 void set_gpio_dir(unsigned, unsigned short);
 void set_gpio_inen(unsigned, unsigned short);
 void set_gpio_polar(unsigned, unsigned short);