util/kconfig: chmod +w before savedefconfig

This prevents a headscratcher when .config in root doesn't have a write
permission bit set which causes a build failure of savedefconfig
not able to write to copied file, for example

*** Error while saving defconfig to:
  build/mainboard/emulation/qemu-i440fx/cbfs-file.eU5E0t.out.tmp2

Change-Id: I2e7d35c9f6e8add3e7438d163850bc5fda5a99b2
Signed-off-by: Richard Marko <srk@48.io>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78415
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin L Roth <gaumless@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>

0 files changed, 0 insertions, 0 deletions