tests/functional: Fix the running test case causes loongarch64 to hang

tests/functional: Fix the running test case causes loongarch64 to hang

There is a bug in the process of resolving the serial port base address
in the fdt of the loongarch VM UEFI. When both serial port information
and rng-seed information are chosen in the fdt, there is a probability
that the serial port base address cannot be resolved correctly.
This problem can be fixed by updating UEFI.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2686
Signed-off-by: Xianglai Li <lixianglai@loongson.cn>
Message-ID: <20241127013438.2206426-1-lixianglai@loongson.cn>
Tested-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>