fix PDK build: use WPA_SUPPLICANT v8 instead of v6

- v6 is not included in PDK

Change-Id: Ia020b01aadd5e68cf1c620de69f8f8f503425eae
diff --git a/BoardConfig.mk b/BoardConfig.mk
index 3801c8d..3216009 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -17,3 +17,5 @@
 MINIMAL_FONT_FOOTPRINT := true
 # Some framework code requires this to enable BT
 BOARD_HAVE_BLUETOOTH := true
+
+WPA_SUPPLICANT_VERSION := VER_0_8_X