ENGR00231273-02 mmc: sdhci: fix failed to call platform exit on removal

ENGR00231273-02 mmc: sdhci: fix failed to call platform exit on removal

Since sdhci_pltfm_data is stored in platform_device_id, but in
sdhci_pltfm_remove, it tried to get sdhci_pltfm_data directly from
pdev->dev.platform_data. It will result that it could not get the correct
sdhci_pltfm_data, so that platform exit will not be called on sdhci module's
removal.

Acked-by: Dong Aisheng <b29396@freescale.com>
Signed-off-by: Ryan QIAN <b32804@freescale.com>