OvmfPkg/Csm/LegacyBootManagerLib: Update to make it build for OVMF

OvmfPkg/Csm/LegacyBootManagerLib: Update to make it build for OVMF

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1811

This commit will update the library's INF file to:

A) Assign a new file GUID;
B) Remove the IntelFramework[Module]Pkg DEC file dependency.

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

Replace the use of LegacyBootManagerLib in IntelFrameworkModulePkg with
the one copied in OvmfPkg within DSC files.

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