The current code would write 'BAR address & size_maks' into PCIe virtual
BAR before updating the virtual BAR's base address when guest writing a
PCIe device's BAR. If the size of a PCIe device's BAR is larger than 4G,
the low 32 bits size_mask for this 64 bits BAR is zero. When ACRN updating
the virtual BAR's base address, the low 32 bits sizing information would
be lost.
This patch saves whether a BAR writing is sizing or not before updating the
virtual BAR's base address.
Tracked-On: #8267
Signed-off-by: Fei Li <fei1.li@intel.com>