mmc: sdhci-msm: enable 64-bit ADMA

The SDHC controller capability was limited to 32-bit ADMA if
the system on chip supported only 32-bit address bus width,
eventhough the controller was 64-bit ADMA capable for potential
memory savings. Remove this limitation on systems that support
larger address bus width.

Change-Id: I79b296bc4dff015dac76036c231d197748aa03cb
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>