spi/topcliff-pch: Fix Kconfig dependencies

The spi-topcliff-pch driver is for a companion chip to the Intel Atom
E600 series processors. These are 32-bit x86 processors so the driver
is only needed on X86_32. Add COMPILE_TEST as an alternative, so that
the driver can still be build-tested elsewhere.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NMark Brown <broonie@linaro.org>

drivers/spi/Kconfig

@@ -505,7 +505,7 @@ config SPI_TEGRA20_SLINK
 
 config SPI_TOPCLIFF_PCH
 	tristate "Intel EG20T PCH/LAPIS Semicon IOH(ML7213/ML7223/ML7831) SPI"
-	depends on PCI
+	depends on PCI && (X86_32 || COMPILE_TEST)
 	help
 	  SPI driver for the Topcliff PCH (Platform Controller Hub) SPI bus
 	  used in some x86 embedded processors.