ARM: OMAP: Fix CONFIG_DEBUG_LL

Fix broken CONFIG_DEBUG_LL. In case of low level debugging
reconfigure some clocks early.

See

http://source.mvista.com/git/gitweb.cgi?p=linux-omap-2.6.git;a=commitdiff;h=3bfb289ccc6c4624fd5ff0381546935e105f4093

too.

Signed-off-by: Dirk Behme <dirk.behme_at_gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>