ArmPlatformPkg/ArmJunoPkg: use a rodata symbol for ReferenceAcpiTable

ArmPlatformPkg/ArmJunoPkg: use a rodata symbol for ReferenceAcpiTable

The ACPI .aslc files contain a ReferenceAcpiTable() function whose
sole purpose is to ensure that the table itself does not get optimized
away. However, when using clang, these dummy functions result in a 4 KB
section alignment requirement, which is silly since everything except
the .data section is discarded later anyway.

So instead, make ReferenceAcpiTable a CONST pointer to VOID*. This way,
we still have a .text section, which is mandatory for the PE/COFF
conversion, but no executable code with small model relocations that
impose additional alignment requirements.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18194 6f19259b-4bc3-4df7-8a09-765794883524