mmc: sdhci: factor out sdhci_pre_dma_transfer() from sdhci_adma_table_pre()

In sdhci_prepare_data(), when SDHCI_REQ_USE_DMA is set, there are two
paths that prepare the data buffers for transfer.  One is when
SDHCI_USE_ADMA is set, and is located inside sdhci_adma_table_pre().
The other is when SDHCI_USE_ADMA is clear, in the else clause of the
above.

Factor out the call to sdhci_pre_dma_transfer() along with its error
checking.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>