apq8016: Add support for UART1 clocks and pinmux

SE HMIBSC board uses UART1 as the main debug console, so add
corresponding clocks and pinmux support. Along with that update
instructions to enable clocks for debug UART support.

Reviewed-by: Caleb Connolly <caleb.connolly@linaro.org>
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
3 files changed