bfin-otp: add BF51x to the supported arch list

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 6f31c94..31be3ac 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -502,7 +502,7 @@
 
 config BFIN_OTP
 	tristate "Blackfin On-Chip OTP Memory Support"
-	depends on BLACKFIN && (BF52x || BF54x)
+	depends on BLACKFIN && (BF51x || BF52x || BF54x)
 	default y
 	help
 	  If you say Y here, you will get support for a character device