StandaloneMmPkg/MmIpl: Call CreatMmHobList() with page aligned size

MmCore ImageSize may be not page aligned, it will be converted to page
aligned for allocating MMRAM to hold MmCore image.

This patch is to call CreatMmHobList() with page aligned size of ImageSize,
otherwise ASSERT (IS_ALIGNED (Length, EFI_PAGE_SIZE)) in
MmIplBuildMmCoreModuleHob() will happen if the input MmCore  ImageSize is
not page aligned.

Signed-off-by: Star Zeng <star.zeng@intel.com>

StandaloneMmPkg/Drivers/StandaloneMmIplPei/StandaloneMmIplPei.c

@@ -1,7 +1,7 @@
 /** @file
   MM IPL that load the MM Core into MMRAM at PEI stage
 
-  Copyright (c) 2024, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2024 - 2025, Intel Corporation. All rights reserved.<BR>
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -795,7 +795,7 @@ ExecuteMmCoreFromMmram (
                     MmFvSize,
                     &MmCoreFileName,
                     ImageContext.ImageAddress,
-                    ImageContext.ImageSize,
+                    EFI_PAGES_TO_SIZE (PageCount),
                     ImageContext.EntryPoint,
                     Block
                     );