galileo: Kconfig: Add pre-configured settings for Galileo's ADC chip

Setting up the right SPI port, its configuration and max frequency.
Also, setting NANO_TIMEOUTS by default as it is required for delayed
operation inside ADC's driver.

Change-Id: I63b2b872ff858f1d80065a94ba3e2f303d279a67
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>