Move all common parts from sdio.c and spi.c to main.c, since they now
can be handled as part of the platform driver.
Signed-off-by: Felipe Balbi <balbi@ti.com>
[forward-ported, cleaned-up and rephrased commit message]
[added a bunch of fixes and a new pdata element]
[moved some new code into main.c as well]
Signed-off-by: Luciano Coelho <coelho@ti.com>