ArmVirtPkg/ArmVirtQemu: add ResetSystem PEIM for upcoming TPM2 support

ArmVirtPkg/ArmVirtQemu: add ResetSystem PEIM for upcoming TPM2 support

As a first step in gradually adding TPM2 support to ArmVirtQemu, add
the TPM2_ENABLE configurable to the [Defines] section, and if it is
set, add the ResetSystem PEIM to the build, along with the library
class references that we will need to support it:
- wire ArmVirtPsciResetSystemPeiLib into the ResetSystem PEIM itself,
  which will be in charge of performing the actual reset
- add PeiResetSystemLib as the common ResetSystemLib resolution for
  PEIM class modules, so that other PEIMs will invoke the PPI
  published by the ResetSystem PEIM.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2560
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>