OvmfPkg/8254TimerDxe: Update to make it build for OVMF

OvmfPkg/8254TimerDxe: Update to make it build for OVMF

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1496

This commit will remove the IntelFrameworkPkg DEC file dependency in the
driver INF file.

A new GUID has been updated for the INF file.

Corresponding changes have been made in OVMF DSC files as well in order to
verify the build.

Please note that a subsequent commit (final patch of the series) will:

A) Add OvmfPkg/8254TimerDxe driver in OVMF FDF files;
B) Remove the consumption of PcAtChipsetPkg/8254TimerDxe driver in OVMF
DSC/FDF files.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>