ARM: dts: Fix wl12xx missing clocks that cause hangs

The tcxo-clock-frequency binding is listed as optional,
but without it the wl12xx used on the torpedo + wireless
may hang.  Scanning also appears broken without this patch.

Signed-off-by: Adam Ford <aford173@gmail.com>
Fixes: 687c2767

 ("ARM: dts: Add minimal support for LogicPD
Torpedo DM3730 devkit")
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Tony Lindgren <tony@atomide.com>