ARM: dts: msm8974: Add nodes for blsp1_uart1 serial port

This serial port is used by LG Nexus 5 (codenammed hammerhead).

Cc: Andy Gross <andy.gross@linaro.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: David Brown <david.brown@linaro.org>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: linux-arm-msm@vger.kernel.org
Cc: devicetree@vger.kernel.org
Signed-off-by: Bhushan Shah <bshah@kde.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>