i386/tdx: Track RAM entries for TDX VM

i386/tdx: Track RAM entries for TDX VM

The RAM of TDX VM can be classified into two types:

 - TDX_RAM_UNACCEPTED: default type of TDX memory, which needs to be
   accepted by TDX guest before it can be used and will be all-zeros
   after being accepted.

 - TDX_RAM_ADDED: the RAM that is ADD'ed to TD guest before running, and
   can be used directly. E.g., TD HOB and TEMP MEM that needed by TDVF.

Maintain TdxRamEntries[] which grabs the initial RAM info from e820 table
and mark each RAM range as default type TDX_RAM_UNACCEPTED.

Then turn the range of TD HOB and TEMP MEM to TDX_RAM_ADDED since these
ranges will be ADD'ed before TD runs and no need to be accepted runtime.

The TdxRamEntries[] are later used to setup the memory TD resource HOB
that passes memory info from QEMU to TDVF.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250508150002.689633-22-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>