Comment 25 for bug 1468628

And the following patch fixes build for cw-3.7 (and I think for cw-3.8, not tested)
diff --git a/Makefile.orig b/Makefile
index 66263c3..7b6ce6f 100644
--- a/Makefile.orig
+++ b/Makefile
@@ -43,8 +43,8 @@ obj-y := compat/
 obj-$(CONFIG_COMPAT_RFKILL) += net/rfkill/

 ifeq ($(BT),)
-obj-$(CONFIG_COMPAT_WIRELESS) += net/wireless/ net/mac80211/
-obj-$(CONFIG_COMPAT_WIRELESS_MODULES) += drivers/net/wireless/
+obj-$(CONFIG_COMPAT_WIRELESS) += drivers/ssb/ drivers/bcma/ net/wireless/ net/mac80211/
+obj-$(CONFIG_COMPAT_WIRELESS_MODULES) += drivers/ssb/ drivers/bcma/ drivers/net/wireless/

 ifeq ($(CONFIG_STAGING_EXCLUDE_BUILD),)
 endif