mmc: sdhci-of-esdhc: fixup PRESENT_STATE read

Since commit 87a18a6a

 ("mmc: mmc: Use ->card_busy() to detect busy
cards in __mmc_switch()") the ESDHC driver is broken:
  mmc0: Card stuck in programming state! __mmc_switch
  mmc0: error -110 whilst initialising MMC card

Since this commit __mmc_switch() uses ->card_busy(), which is
sdhci_card_busy() for the esdhc driver. sdhci_card_busy() uses the
PRESENT_STATE register, specifically the DAT0 signal level bit. But the
ESDHC uses a non-conformant PRESENT_STATE register, thus a read fixup is
required to make the driver work again.

Signed-off-by: Michael Walle <michael@walle.cc>
Fixes: 87a18a6a

 ("mmc: mmc: Use ->card_busy() to detect busy cards in __mmc_switch()")
Acked-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: <stable@vger.kernel.org> # v4.8+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>