mmc: dwc: fix some build warning when use ARM64 platform

dwc driver only consider 32bit platform before, there is some warning
when we use 64bit platform, fix it.

BUG=None
TEST=None
BRANCH=None

Change-Id: I50d427368fc1e016cda7c75a2e05e12d7cef7bc6
Signed-off-by: Lin Huang <hl@rock-chips.com>
Reviewed-on: https://chromium-review.googlesource.com/330284
Commit-Ready: Vadim Bendebury <vbendeb@chromium.org>
Tested-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-by: Stefan Reinauer <reinauer@chromium.org>
1 file changed