scripts/setlocalversion: Reinstate .scmversion support

scripts/setlocalversion: Reinstate .scmversion support

The .scmversion is used by oe-core to append U-Boot version string.

LOCALVERSION is not fully compatible replacement as it adds trailing
"-dirty" string at the end of version string in case the U-Boot git
tree contains uncommitted changes. This behavior itself is correct.
However, OE builds do clone U-Boot sources from git and may apply
additional patches on top, which are not tracked in U-Boot git tree,
but rather in the OE metalayer git tree, which leads to the addition
of "-dirty" string as well.

The .scmversion used by oe-core used to replace the version string
suffix fully, including the "-dirty" string. Reinstate support for
the .scmversion to let OE core do exactly that as it used to do it.

Fixes: 5c02350fa03d ("scripts/setlocalversion: sync with linux v6.9")
Signed-off-by: Marek Vasut <marex@denx.de>