ArmPkg: MmCommunicationDxe: Update MM communicate `CommSize` check

ArmPkg: MmCommunicationDxe: Update MM communicate `CommSize` check

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3751

Current MM communicate routine from ArmPkg would conduct few checks prior
to proceeding with SMC calls. However, the inspection step is different
from PI specification.

This patch updated MM communicate input argument inspection routine to
assure `CommSize` represents "the size of the data buffer being passed
in" instead of the size of the data being used from data buffer, as
described by section `EFI_MM_COMMUNICATION2_PROTOCOL.Communicate()` in PI
specification.

Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Cc: Michael Kubacki <michael.kubacki@microsoft.com>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Kun Qin <kuqin12@gmail.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>