at91_softpwm: declare the needed Makefile variables

kernel/at91_softpwm/Makefile

 
-# Trivial makefile for 2.6 modules
-
-#LINUX ?= /lib/modules/$(shell uname -r)/build
-
 obj-m = at91_softpwm.o 
-
 at91_softpwm-objs := fiq-asm.o fiq-at91sam92.o fiq-module.o softpwm_core.o
 
-all:
-	$(MAKE) -C $(LINUX) M=$(shell /bin/pwd) modules
+export ARCH ?= arm
+export CROSS_COMPILE ?= $(CROSS_COMPILE_ARM)
 
+all modules:
+	$(MAKE) CONFIG_DEBUG_SECTION_MISMATCH=y \
+		-C $(LINUX) SUBDIRS=$(shell /bin/pwd) modules
+
+# We might "$(MAKE) -C $(LINUX)" but "make clean" with no LINUX defined
+# is sometimes useful to have
 clean:
-	$(MAKE) -C $(LINUX) clean M=$(shell /bin/pwd)
-	rm -f Module.symvers modules.order *~
-#	$(MAKE) -C doc terse
+	rm -f *.mod.c *.o *.ko .*cmd Module.symvers modules.order
+	rm -rf .tmp_versions
+