OvmfPkg/IoMmuDxe: convert UINTN arguments to UINT64 for the %Lx fmt spec

OvmfPkg/IoMmuDxe: convert UINTN arguments to UINT64 for the %Lx fmt spec

The portable way to print UINTN values is to use the %Lx format specifier,
and to convert the values to UINT64. The second step is currently missing,
add it.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>