The same partition setting code can be used for both SPI and SDIO
modes, if we remove the spi-specific commands and use the more
generic buffer write routines. Do that and move it to io.c
since it deals with register/memory address offsets.
Signed-off-by: Bob Copeland <me@bobcopeland.com> Signed-off-by: Kalle Valo <kalle.valo@nokia.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>