OvmfPkg/OvmfPkg.dec: Adjust PcdMptScsiStallPerPollUsec token value

OvmfPkg/OvmfPkg.dec: Adjust PcdMptScsiStallPerPollUsec token value

The token value of PcdMptScsiStallPerPollUsec should be 0x3a since the
previous token value is 0x39.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Nikita Leshenko <nikita.leshchenko@oracle.com>
Signed-off-by: Gary Lin <glin@suse.com>
Message-Id: <20200715082031.30978-1-glin@suse.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
[lersek@redhat.com: clarify subject, fix typos in commit message]
Reviewed-by: Laszlo Ersek <lersek@redhat.com>