As an implementation of an industry specification-defined interface,
ArmSvcLib is more appropriately placed in MdePkg.
This update relocates both the header definition and the implementation
of ArmSvcLib to MdePkg, thereby supporting the supervisor 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>
