Tweak mx6qsabrelite installer to handle U-Boot binary name change

The name of the binary produced by U-Boot for the SABRE Lite has changed from u-boot.imx to u-boot-dtb.imx with the latest update to U-Boot. This is causing the creation of the U-Boot installer to fail and would also cause installation to fail.

Tweak the name to enable the U-Boot installer to be correctly built and be able to install the U-Boot binary.

Signed-off-by: Martyn Welch martyn.welch@collabora.com