mmc: sdhci-iproc: Apply caps from bcm2835-mmc driver

Since the mmc module on bcm2835 neither provide a capabilities register nor
free documentation we must rely on the downstream implementation [1].

So enable the following capabilities for bcm2835:

MMC_CAP_MMC_HIGHSPEED
MMC_CAP_SD_HIGHSPEED
MMC_CAP_DRIVER_TYPE_A
MMC_CAP_DRIVER_TYPE_C

[1] - https://github.com/raspberrypi/linux/blob/rpi-4.4.y/drivers/mmc/host/bcm2835-mmc.c



Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>