fsp_baytrail: Fix ACPI 'Object is not referenced' warnings

The ACPI compiler is trying to be helpful in letting us know that we're
not using various fields in the MCRS 'ResourceTemplate' when we define
it inside of the _CRS method.  Since we're not intending to use those
objects in the method, it shouldn't be an issue, but the warning is
annoying.  Moving the creation of the MCRS object to outside of the
_CRS method and referencing it from there solves this problem.

Change-Id: I222642e9a93f3078b46ed74f57b83a5834657abf
Signed-off-by: Martin Roth <martin.roth@se-eng.com>
Reviewed-on: http://review.coreboot.org/7499
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>