Revert "iommu: make inclusion of arm/arm-smmu-v3 directory conditional"

This reverts commit e436576.

That commit is very broken, and seems to have missed the fact that
CONFIG_ARM_SMMU_V3 is not just a yes-or-no thing, but also can be
modular.

So it caused build errors on arm64 allmodconfig setups:

  ERROR: modpost: "arm_smmu_make_cdtable_ste" [drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.ko] undefined!
  ERROR: modpost: "arm_smmu_make_s2_domain_ste" [drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.ko] undefined!
  ERROR: modpost: "arm_smmu_make_s1_cd" [drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-test.ko] undefined!
  ...

(and six more symbols just the same).

Link: https://lore.kernel.org/all/CAHk-=wh4qRwm7AQ8sBmQj7qECzgAhj4r73RtCDfmHo5SdcN0Jw@mail.gmail.com/
Cc: Joerg Roedel <[email protected]>
Cc: Rolf Eike Beer <[email protected]>
Cc: Lu Baolu <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: torvalds

drivers/iommu/arm/Makefile

@@ -1,3 +1,2 @@
 # SPDX-License-Identifier: GPL-2.0
-obj-y += arm-smmu/
-obj-$(CONFIG_ARM_SMMU_V3) += arm-smmu-v3/
+obj-y += arm-smmu/ arm-smmu-v3/

drivers/iommu/arm/arm-smmu-v3/Makefile

@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
-obj-y += arm_smmu_v3.o
+obj-$(CONFIG_ARM_SMMU_V3) += arm_smmu_v3.o
 arm_smmu_v3-y := arm-smmu-v3.o
 arm_smmu_v3-$(CONFIG_ARM_SMMU_V3_IOMMUFD) += arm-smmu-v3-iommufd.o
 arm_smmu_v3-$(CONFIG_ARM_SMMU_V3_SVA) += arm-smmu-v3-sva.o