oe-setup-build: TEMPLATECONF were not applied correctly

oe-setup-build: TEMPLATECONF were not applied correctly

Since a recent change to support dash, cmd_base is a set of several
commands, separated by newlines.
TEMPLATECONF was only effective for the first command in that set,
which is not where it's needed.
Putting it on its own line will ensure that it's present for
everything in cmd_base.

Signed-off-by: Logan Gallois <logan.gallois@hexagon.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>