This adjusts the code added in commit
c90bd74ebb ("boot/barebox: pass required
environment variables for reproducible build") to explicitly set the
timezone when calculating KBUILD_BUILD_TIMESTAMP, like is already done
in linux/linux.mk.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 11e75ecbf0)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>