spi: s3c drivers shouldn't care about spi_board_info

The two S3C SPI master drivers got merged without much review, so I just
noticed that they're doing something that the SPI core code is responsible
for, rather than any adapter driver: they try to register SPI devices.

This removes that support from those drivers so they act normally.
Interestingly, none of the current boards are affected.  So it's a net code
shrink with no loss of functionality.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>