mxs: Kconfig: Remove TARGET_XFI3 symbol

The xfi3 target has been removed by commit 539fba2c10e7 ("arm:
Remove xfi3 board"), but it missed to remove an entry from the
mxs Kconfig.

Remove it.

Signed-off-by: Fabio Estevam <festevam@denx.de>
1 file changed