uboot-imx

multiconfig.sh: replace GNU sed specific match

A SPL/TPL enabled target would was not recognized as
such by BSD sed, since it relies on a GNU extension.
Instead of or-ing just spell out both matches.

Cc: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
Acked-by: Masahiro Yamada <yamada.m@jp.panasonic.com>