iommu/amd: Enable support for up to 2K interrupts per function

iommu/amd: Enable support for up to 2K interrupts per function

AMD IOMMU optionally supports up to 2K interrupts per function on newer
platforms. Support for this feature is indicated through Extended
Feature 2 Register (MMIO Offset 01A0h[NumIntRemapSup]). Allocate 2K IRTEs
per device when this support is available.

Co-developed-by: Sairaj Kodilkar <sarunkod@amd.com>
Signed-off-by: Sairaj Kodilkar <sarunkod@amd.com>
Signed-off-by: Kishon Vijay Abraham I <kvijayab@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20250307095822.2274-5-sarunkod@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>