ArmPkg: ensure DebugAgentVectorTable is 2K-aligned

ArmPkg: ensure DebugAgentVectorTable is 2K-aligned

We force alignment to 2K after generating the DebugAgentVectorTable
symbol, and hence DebugAgentVectorTable itself may not be 2K-aligned,
and table entries may not be at the correct offset from the
DebugAgentVectorTable base address.

Fix this by forcing alignment before generating the
DebugAgentVectorTable symbol.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18865 6f19259b-4bc3-4df7-8a09-765794883524