iommu/amd: Add sanity check for interrupt remapping table length macros

iommu/amd: Add sanity check for interrupt remapping table length macros

Currently, macros related to the interrupt remapping table length are
defined separately. This has resulted in an oversight in which one of
the macros were missed when changing the length. To prevent this,
redefine the macros to add built-in sanity check.

Also, rename macros to use the name of the DTE[IntTabLen] field as
specified in the AMD IOMMU specification. There is no functional change.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Will Deacon <will@kernel.org>
Cc: Jerry Snitselaar <jsnitsel@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Link: https://lore.kernel.org/r/20201210162436.126321-1-suravee.suthikulpanit@amd.com
Signed-off-by: Will Deacon <will@kernel.org>