configs/beaglebone_qt5: drop U-Boot tools
Commit e2520d0ff3d8e ("configs/beaglebone_qt5: bump kernel and U-Boot,
add weston") selected host-uboot-tools with FIT support to create the
images. They are no longer necessary now.
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>