UPSTREAM: kbuild: dummy-tools: adjust to scripts/cc-version.sh

Commit aec6c60a ("kbuild: check the minimum compiler version in
Kconfig") changed how the script detects the compiler version.

Get 'make CROSS_COMPILE=scripts/dummy-tools/' back working again.

Bug: 254441685
Fixes: aec6c60a ("kbuild: check the minimum compiler version in Kconfig")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
(cherry picked from commit f9bc754b)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: I0ce942de1dbc16dd8b974296bc2fd3cc703e49e5