CHROMIUM: ARM: cros5250: Fix the name of the 32k peripheral clock

CHROMIUM: ARM: cros5250: Fix the name of the 32k peripheral clock

The name of this clock was corrected in my fixup to this CL:
  https://gerrit-int.chromium.org/18444
...unfortunately, I hadn't realized that I also needed to update the
device tree.  This fixes it.

BUG=chrome-os-partner:8923
TEST=On Daisy can now see WiFi card.  AKA, see this in boot messages:
  [    9.640000] mmc2: new high speed SDIO card at address 0001
TEST=No longer see errors about 32khz clock in dmesg.  Was seeing:
  [    0.700000] max77686 0-0009: No configuration data for regulator EN32KHZ

Change-Id: Ia113ebe416b07a0355fe45995439e5043bdce46e
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-on: https://gerrit-int.chromium.org/19091
Tested-by: Doug Anderson <dianders@google.com>
Reviewed-by: Sam Leffler <sleffler@google.com>
Commit-Ready: Doug Anderson <dianders@google.com>