stand: Update riscv efi booting to edk2 includes

Update to include the right includes for the riscv protocol to get the
hypervisor details.

Note: I expanded the GUID inline rather than using a #define because
there was none. This is only listed in UefiCpuPkg/UefiCpuPkg.dec, so
include it here inline until we can automate using those files.

Fixes: 43b8edb32051
Sponsored by: Netflix