api: New SPI API

Such API improves many aspects of the former API by reducing the number
of function, allowing more buffer flexibility etc... This leads in
better memory usag and performance as well.

However, as this will take sometime to get into use, the former API is
still present and is the one enabled by default.

Jira: ZEP-852
Jira: ZEP-287
Jira: ZEP-1725

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