iommu/vt-d: Remove unused function intel_svm_capable()

This is unused since commit 40483774

 ("iommu/vt-d: Use
iommu_sva_alloc(free)_pasid() helpers").

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20220216113851.25004-1-yuehaibing@huawei.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20220301020159.633356-12-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>