mmc: core: Fix voltage select in DDR mode

mmc: core: Fix voltage select in DDR mode

This patch fixes the wrong comparison before setting the interface
voltage in DDR mode.

The assignment to the variable ddr before comaprison is either
ddr = MMC_1_2V_DDR_MODE; or ddr == MMC_1_8V_DDR_MODE. But the comparison
is done with the extended csd value if ddr == EXT_CSD_CARD_TYPE_DDR_1_2V.

Signed-off-by: Girish K S <[email protected]>
Acked-by: Subhash Jadavani <[email protected]>
Acked-by: Philip Rakity <[email protected]>
Cc: <[email protected]>
Signed-off-by: Chris Ball <[email protected]>