dtc: preserve version also from shallow git clones

dtc: preserve version also from shallow git clones

Since switch from Makefile to meson based build,
the version is no longer hardcoded but queried from git tag.

This works only if git history is available.
When shallow tarballs are used, tag is not available.

Example error for trusted-firmware-a from meta-arm:
dtc version too old (039a994), you need at least version 1.4.4

Backport also patch to fix version in meson file.

Signed-off-by: Peter Marko <peter.marko@siemens.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>