i.MX31: Correct comments on CONFIG_DEBUG_LL.

Several comments in board config files stated "mandatory for
CONFIG_LL_DEBUG" but the correct name is CONFIG_DEBUG_LL.

Signed-off-by: Magnus Lilja <lilja.magnus@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
7 files changed