Add support for a Freescale non-CPM SPI controller

This patch adds support for the SPI controller found on Freescale PowerPC
processors such as the MCP834x family.  Additionally, a new config option,
CONFIG_HARD_SPI, is added for general purpose SPI controller use.

Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>