Platform/ARM/SgiPkg: sync with edk2 StandaloneMmCpu path change
Synchronize with edk2 package where StandaloneMmCpu component has moved
from StandaloneMmPkg/Drivers/StandaloneMmCpu/AArch64/StandaloneMmCpu.inf
to StandaloneMmPkg/Drivers/StandaloneMmCpu/StandaloneMmCpu.inf
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Cc: Sughosh Ganu <sughosh.ganu@linaro.org>
Cc: Thomas Abraham <thomas.abraham@arm.com>
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>