Actually fix mindspeed drivers Makefile.

Change-Id: I7f1e24e68ea074726317b1f1acfaebd5424c7a3e
diff --git a/Makefile b/Makefile
index 95541b8..de88258 100644
--- a/Makefile
+++ b/Makefile
@@ -12,10 +12,10 @@
 		$(DESTDIR)/sbin/hotplug
 
 pfe_ctrl/all:
-	$(MAKE) -C $(@D) $(LINUX_MAKE_FLAGS) KERNELDIR=$(LINUX_DIR) PFE_DIR=../pfe
+	$(MAKE) -C pfe_ctrl $(LINUX_MAKE_FLAGS) KERNELDIR=$(LINUX_DIR) PFE_DIR=../pfe
 
 pfe_ctrl/install:
-	$(MAKE) -C $(LINUX_DIR) $(LINUX_MAKE_FLAGS) M=$(PWD)/$(@D) modules_install
+	$(MAKE) -C $(LINUX_DIR) $(LINUX_MAKE_FLAGS) M="$(shell /bin/pwd)/pfe_ctrl" modules_install
 
 %/all:
 	$(MAKE) -C $* all