This adds the dtbs_install make target to arm64. The target has been
introduced already to arch/arm with the following commit:
f4d4ffc03e kbuild: dtbs_install: new make target
Implementation for arm64 is the same as for arm.
With 'dtbs_install' all config enabled dtb files are installed to
either the INSTALL_DTBS_PATH directory or the default location:
$INSTALL_PATH/dtbs/$KERNELRELEASE
Signed-off-by: Robert Richter <rrichter@cavium.com>
862f464a54