OvmfPkg, ArmVirtualizationPkg: clean up XenHypercallLib names

OvmfPkg, ArmVirtualizationPkg: clean up XenHypercallLib names

Perform the following renames in order to stick with edk2 tradition more
closely:

  XenHypercallLibArm, XenHypercallLibIntel  ->  XenHypercallLib
  XenHypercallIntel                         ->  X86XenHypercall

In addition, we unify the INF files.

This patch modifies ArmVirtualizationPkg and OvmfPkg at once, in order to
keep both bisectable (client code shouldn't break).

Suggested-by: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16998 6f19259b-4bc3-4df7-8a09-765794883524