As an implementation of an industry specification-defined interface,
ArmSmcLib is more appropriately placed in MdePkg.
This update relocates both the header definition and the implementation
of ArmSmcLib to MdePkg, thereby supporting the monitor call primitives
for all other packages that depend on this interface.
Continuous-integration-options: PatchCheck.ignore-multi-package
Signed-off-by: Kun Qin <kun.qin@microsoft.com>
