mmc: sdhci-omap: Fix busy detection by enabling MMC_CAP_NEED_RSP_BUSY

It has turned out that the sdhci-omap controller requires the R1B response,
for commands that has this response associated with them. So, converting
from an R1B to an R1 response for a CMD6 for example, leads to problems
with the HW busy detection support.

Fix this by informing the mmc core about the requirement, via setting the
host cap, MMC_CAP_NEED_RSP_BUSY.

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: Anders Roxell <anders.roxell@linaro.org>
Reported-by: Faiz Abbas <faiz_abbas@ti.com>
Cc: <stable@vger.kernel.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Tested-by: Faiz Abbas <faiz_abbas@ti.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>