ACPI: tables: Enable FPDT on LoongArch

FPDT provides system- and application-readable performance statistics,
useful for profiling and analyzing boot-time performance. FPDT table
support is now available as a pending patch at the EDK II upstream [1]
and has been tested on real hardware such as Loongson XA61200_V1.1 and
XB612B0_V1.2 with patched firmware.

We have also cross checked systemd-analyze(1) against a stop watch and
the `dp' command in EFI Shell to see that the timing information are
correct.

Now that the functionality of FPDT is verified on LoongArch hardware,
list LOONGARCH as a possible dependency, allowing it to be enabled.

Link: https://github.com/tianocore/edk2/pull/12378

 [1]
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
[ rjw: Subject tweak ]
Link: https://patch.msgid.link/20260401135311.1737958-2-xry111@xry111.site


Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>