The UART disable code was causing a hang and was worked around with a

The UART disable code was causing a hang and was worked around with a
return that skipped the disable code. This patch removes the return and
fixes the UART disable code.

The problem was that the disable code was ORing bits into the Legacy_IO
MSR causing issues with the LPC SIOs init code that would manifest as a
hang because the IO would not be decoded correctly. ANDing to clear the
bits fixes the issue.

Signed-off-by: Marc Jones <marc.jones@amd.com>
Acked-by: Ronald G. Minnich <rminnich@gmail.com>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@2706 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1