ArmPkg: merge ArmGicV[23]Lib.h into ArmGicLib.h

ArmPkg: merge ArmGicV[23]Lib.h into ArmGicLib.h

Before splitting off ArmGicArchLib and moving it out of
ArmPkg/Drivers/ArmGic into ArmPkg/Library, make sure that the
GIC specific declarations it depends on are not hidden away in
local headers "GicV2/GicV2Lib.h" and "GicV3/GicV3Lib.h".

So merge them with <Library/ArmGicLib.h>. This is entirely
appropriate, since this is not a header that declares a public
interface into ArmGicLib, but defines implementation internals.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
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@18097 6f19259b-4bc3-4df7-8a09-765794883524