Salmon: Updated defconfig to include more items
cl15: Use weak functions to allow SPI boot flash replacement

Baseboards can re-route the SPI CS pin if they want to use multiple
devices on the SPI bus. So allow them to override these functions if
necessary
Salmon: Override spi flash routines

Allows SST25L spi flash mtd device to appear in /proc/mtd properly
Whitespace: Minor whitespace cleanup