ArmPkg: update InvalidateInstructionCacheRange to flush only to PoU

ArmPkg: update InvalidateInstructionCacheRange to flush only to PoU

This patch updates the ArmPkg variant of InvalidateInstructionCacheRange to
flush the data cache only to the point of unification (PoU). This improves
performance and also allows invalidation in scenarios where it would be
inappropriate to flush to the point of coherency (like when executing code
from L2 configured as cache-as-ram).

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Eugene Cohen <eugene@hp.com>
Added AARCH64 and ARM/GCC implementations of the above.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Eugene Cohen <eugene@hp.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19174 6f19259b-4bc3-4df7-8a09-765794883524