Fix the output filenames of the combined device tree blobs generated by
applying *-csi2-dual-imx219-* overlays on the base dtbs during compile
test.

Fixes: f767eb91 ("arm64: dts: ti: k3-j721e-sk: Add overlay for IMX219")
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Reviewed-by: Aradhya Bhatia <a-bhatia1@ti.com>
Reviewed-by: Devarsh Thakkar <devarsht@ti.com>
Link: https://lore.kernel.org/r/104fbdbc-a3f6-091a-72f4-17d4fa24ad92@ti.com/Signed-off-by: Nishanth Menon <nm@ti.com>