Blackfin arch: split board selection off into mach subdirs

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

diff --git a/arch/blackfin/mach-bf548/boards/Kconfig b/arch/blackfin/mach-bf548/boards/Kconfig
new file mode 100644
index 0000000..0571290
--- /dev/null
+++ b/arch/blackfin/mach-bf548/boards/Kconfig
@@ -0,0 +1,12 @@
+choice
+	prompt "System type"
+	default BFIN548_EZKIT
+	help
+	  Select your board!
+
+config BFIN548_EZKIT
+	bool "BF548-EZKIT"
+	help
+	  BFIN548-EZKIT board support.
+
+endchoice