iommu/msm: Mark driver BROKEN

The MSM IOMMU driver unconditionally calls bus_set_iommu(), which is a
very stupid thing to do on multi-platform kernels. While marking the
driver BROKEN may seem a little extreme, there is no other way to make
the driver skip initialization. One of the problems is that it doesn't
have devicetree binding documentation and the driver doesn't contain a
struct of_device_id table either, so no way to check that it is indeed
valid to set up the IOMMU operations for this driver.

This fixes a problem on Tegra20 where the DRM driver will try to use the
obviously non-existent MSM IOMMU.

Marking the driver BROKEN shouldn't do any harm, since there aren't any
users currently. There is no struct of_device_id table, so the device
can't be instantiated from device tree, and I couldn't find any code
that would instantiate a matching platform_device either, so the driver
is effectively unused.

Reported-by: Nicolas Chauvet <kwizart@gmail.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: Olav Haugan <ohaugan@codeaurora.org>
Acked-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/Kconfig

@@ -63,6 +63,7 @@ config MSM_IOMMU
 	bool "MSM IOMMU Support"
 	depends on ARM
 	depends on ARCH_MSM8X60 || ARCH_MSM8960 || COMPILE_TEST
+	depends on BROKEN
 	select IOMMU_API
 	help
 	  Support for the IOMMUs found on certain Qualcomm SOCs.