mmc: remove unnecessary platform_set_drvdata()

The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 0998d0631001288a5974afc0b2a5f568bcdecb4d
(device-core: Ensure drvdata = NULL when no driver is bound).
Thus, it is not needed to manually clear the device driver data to NULL.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Sonic Zhang <sonic.zhang@analog.com>
Acked-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --cc drivers/mmc/host/android-goldfish.c
Simple merge

diff --cc drivers/mmc/host/atmel-mci.c
Simple merge

diff --cc drivers/mmc/host/au1xmmc.c
Simple merge

diff --cc drivers/mmc/host/bfin_sdh.c
Simple merge

diff --cc drivers/mmc/host/davinci_mmc.c
Simple merge

diff --cc drivers/mmc/host/dw_mmc-pltfm.c
Simple merge

diff --cc drivers/mmc/host/jz4740_mmc.c
Simple merge

diff --cc drivers/mmc/host/mvsdio.c
Simple merge

diff --cc drivers/mmc/host/mxcmmc.c
Simple merge

diff --cc drivers/mmc/host/mxs-mmc.c
Simple merge

diff --cc drivers/mmc/host/omap.c
Simple merge

diff --cc drivers/mmc/host/omap_hsmmc.c
Simple merge

diff --cc drivers/mmc/host/pxamci.c
Simple merge

diff --cc drivers/mmc/host/rtsx_pci_sdmmc.c
Simple merge

diff --cc drivers/mmc/host/sdhci-acpi.c
Simple merge

diff --cc drivers/mmc/host/sdhci-pltfm.c
Simple merge

diff --cc drivers/mmc/host/sdhci-pxav2.c
Simple merge

diff --cc drivers/mmc/host/sdhci-pxav3.c
Simple merge

diff --cc drivers/mmc/host/sdhci-s3c.c
Simple merge

diff --cc drivers/mmc/host/sdhci-spear.c
Simple merge

diff --cc drivers/mmc/host/sh_mmcif.c
Simple merge

diff --cc drivers/mmc/host/tmio_mmc.c
Simple merge

diff --cc drivers/mmc/host/wmt-sdmmc.c
Simple merge