ArmPkg: remove DebugUncachedMemoryAllocationLib

ArmPkg: remove DebugUncachedMemoryAllocationLib

The debug implementation of the UncachedMemoryAllocationLib library
class relies on the creation of an uncached alias of a memory range,
while keeping the original cached mapping, but with read-only attributes
to trap inadvertent write accesses.

This is not a terribly good idea, given that the ARM architecture does
not allow mismatched attributes, and so creating them deliberately is
not something we should encourage by doing it in reference code.

So remove the library, and replace all references to it with a reference
to the non-debug version (unless the platform does not require a resolution
for it in the first place, in which case all UncachedMemoryAllocationLib
references can be removed altogether).

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>