mmc: sdhci: Fix max segments and max req size for PIO mode

When ADMA is disabled the max segments and max req size were not set
properly, set them right to use the driver in PIO mode.

Change-Id: I754c30c017062540335f96480d103f054cc38084
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>