ARM: OMAP2: HSMMC: explicit fields to declare cover/card detect pin

board-rx51 has no card detect pin in the mmc slot, but can detect that
the (cell-phone) cover has been removed and the card is accessible.
The semantics between cover/card detect differ, the gpio on the slot
informs you after the card has been removed, cover removal does not
necessarily mean that the card has been removed.
This means different code paths are necessary. To complete this we
also want different fields in the platform data for cover and card
detect. This separation is not pushed all the way down into struct
omap2_hsmmc_info which is used to initialize the platform data.
If we did that we had to go over all board files and set the new
gpio_cod pin to -EINVAL. If we forget one board or some out-of-tree
archicture forgets that the default '0' is used which is a valid pin
number.

Signed-off-by: Andreas Fenkart <afenkart@gmail.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>