OvmfPkg/IoMmuDxe: Rename AmdSevIoMmu to CcIoMmu

OvmfPkg/IoMmuDxe: Rename AmdSevIoMmu to CcIoMmu

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4171

IoMmuDxe once was designed to support DMA operation when SEV is enabled.
After TDX is enabled in IoMmuDxe, some files' name in IoMmuDxe need to
be more general. So this patch rename:
  AmdSevIoMmu.h -> CcIoMmu.h
  AmdSevIoMmu.c -> CcIoMmu.c

Accordingly there are some udates in IoMmuDxe.c and IoMmuDxe.inf.

Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>