eap_proxy: Use unique Makefile names for Android and non-Android

Rename the eap_proxy_*.mk file to eap_proxy_*.mak for non-Android builds
so that the same eap_proxy implementation can be more easily included in
the same directory for both cases.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

wpa_supplicant/Makefile

@@ -515,7 +515,7 @@ endif
 ifdef CONFIG_EAP_PROXY
 CFLAGS += -DCONFIG_EAP_PROXY
 OBJS += ../src/eap_peer/eap_proxy_$(CONFIG_EAP_PROXY).o
-include eap_proxy_$(CONFIG_EAP_PROXY).mk
+include eap_proxy_$(CONFIG_EAP_PROXY).mak
 CONFIG_IEEE8021X_EAPOL=y
 endif