spi: Move spi code from Documentation to tools

Jon Corbet requested this code moved with the last changeset,
https://lkml.org/lkml/2015/3/1/144,
but the patch was not applied because it missed the Makefile.
Moved spidev_test, spidev_fdx and their Makefile infrastructure.
Signed-off-by: Joshua Clayton <stillcompiling@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/Makefile

 subdir-y := accounting auxdisplay blackfin connector \
 	filesystems filesystems ia64 laptops mic misc-devices \
-	networking pcmcia prctl ptp spi timers vDSO video4linux \
+	networking pcmcia prctl ptp timers vDSO video4linux \
 	watchdog

Documentation/spi/Makefile

-# List of programs to build
-hostprogs-y := spidev_test spidev_fdx
-
-# Tell kbuild to always build the programs
-always := $(hostprogs-y)
-
-HOSTCFLAGS_spidev_test.o += -I$(objtree)/usr/include
-HOSTCFLAGS_spidev_fdx.o += -I$(objtree)/usr/include

tools/Makefile

@@ -17,6 +17,7 @@ help:
 	@echo '  lguest     - a minimal 32-bit x86 hypervisor'
 	@echo '  perf       - Linux performance measurement and analysis tool'
 	@echo '  selftests  - various kernel selftests'
+	@echo '  spi        - spi tools'
 	@echo '  turbostat  - Intel CPU idle stats and freq reporting tool'
 	@echo '  usb        - USB testing tools'
 	@echo '  virtio     - vhost test module'
@@ -48,7 +49,7 @@ acpi: FORCE
 cpupower: FORCE
 	$(call descend,power/$@)
 
-cgroup firewire hv guest usb virtio vm net iio: FORCE
+cgroup firewire hv guest spi usb virtio vm net iio: FORCE
 	$(call descend,$@)
 
 liblockdep: FORCE
@@ -109,7 +110,7 @@ acpi_clean:
 cpupower_clean:
 	$(call descend,power/cpupower,clean)
 
-cgroup_clean hv_clean firewire_clean lguest_clean usb_clean virtio_clean vm_clean net_clean iio_clean:
+cgroup_clean hv_clean firewire_clean lguest_clean spi_clean usb_clean virtio_clean vm_clean net_clean iio_clean:
 	$(call descend,$(@:_clean=),clean)
 
 liblockdep_clean:
@@ -134,7 +135,7 @@ freefall_clean:
 	$(call descend,laptop/freefall,clean)
 
 clean: acpi_clean cgroup_clean cpupower_clean hv_clean firewire_clean lguest_clean \
-		perf_clean selftests_clean turbostat_clean usb_clean virtio_clean \
+		perf_clean selftests_clean turbostat_clean spi_clean usb_clean virtio_clean \
 		vm_clean net_clean iio_clean x86_energy_perf_policy_clean tmon_clean \
 		freefall_clean
 

tools/spi/Makefile

+all: spidev_test spidev_fdx
+
+clean:
+	$(RM) spidev_test spidev_fdx