x86: fsp: Only FSP2 has INIT_PHASE_END_FIRMWARE

For FSP1, there is no such INIT_PHASE_END_FIRMWARE.

Move board_final_cleanup() to fsp2 directory.

Fixes: 7c73cea4 ("x86: Notify the FSP of the 'end firmware' event")
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested on chromebook_coral, chromebook_samus, chromebook_link, minnowmax
Tested-by: Simon Glass <sjg@chromium.org>