Attached patch adds sane compile-time defaults via Kconfig options for CMOS options
 'iommu, ECC_memory, max_mem_clock, hw_scrubber, interleave_chip_selects'.
Avoid build error if any of these CMOS options are not defined.
Checks the return value of 'get_option(..)', if not done yet, and
if CMOS option not exist grab a Kconfig option otherwise a hardcoded
value is used.

Signed-off-by: Josef Kellermann <seppk@arcor.de>