mmc: host: omap_hsmmc: add code for special init of wl1251 to get rid of pandora_wl1251_init_card

Pandora_wl1251_init_card was used to do special pdata based
setup of the sdio mmc interface. This does no longer work with
v4.7 and later. A fix requires a device tree based mmc3 setup.

Therefore we move the special setup to omap_hsmmc.c instead
of calling some pdata supplied init_card function.

The new code checks for a DT child node compatible to wl1251
so it will not affect other MMC3 use cases.

Generally, this code was and still is a hack and should be
moved to mmc core to e.g. read such properties from optional
DT child nodes.

Fixes: 81eef6ca

 ("mmc: omap_hsmmc: Use dma_request_chan() for requesting DMA channel")
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Cc: <stable@vger.kernel.org> # v4.7+
[Ulf: Fixed up some checkpatch complaints]
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>