mmc: core: Re-use code for MMC_CAP2_DETECT_ON_ERR in polling mode

Previously the MMC_CAP2_DETECT_ON_ERR was invented for detecting
slow card removal. In was never a realy good solution and a proper
fix has been merged using gpio debouncing instead. We remove this
cap in this patch.

Although when using polling card detect mode, the code invented for
MMC_CAP2_DETECT_ON_ERR is re-used to complete card removal in an
earlier phase. There are no need waiting for the polling timeout to
elapse in this case.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Liu <kliu5@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>