scripts: build-all: Build dtbs as part of 'all' builds
scripts: build-all: Build dtbs as part of 'all' builds

Make sure to build the dtb targets so that these are tested as part of
building all targets.

Change-Id: I351527d197ef6a60fefe43f3a16b34be86a74dd1
Signed-off-by: David Brown <67bb63793f66c3c3797af10faa739beca3aeb927@codeaurora.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas