tests: add a test to verify UEFI boot on x86_64 targets.

add a config CONFIG_QEMU_UEFI_BOOT to indicate whether
the qemu will use UEFI bootable method;
add a new test "sample.basic.helloworld.uefi" to verify
UEFT bootable method on qemu_x86_64 platform.

Signed-off-by: Chen Peng1 <peng1.chen@intel.com>