ARM: dts: qcom: msm8974-hammerhead: add WiFi support

This patch adds WiFi support to the LG Nexus 5 (hammerhead) phone.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
[masneyb@onstation.org: Enabled wlan_regulator_pin and wlan_sleep_clk_pin]
Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Signed-off-by: Andy Gross <andy.gross@linaro.org>