spi: McSPI saves CHCONFx too

Previous restore was lazy and only restored CHxCONF when it was needed by
a specific chip select.  This could cause occasional errors on an SPI bus
where multiple chip selects are in use.

Signed-off-by: Tero Kristo <tero.kristo@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>