ARM: debug: qcom: add UART addresses to Kconfig help for IPQ4019

Add information about the IPQ4019 debug UART physical and virtual
addresses in the DEBUG_QCOM_UARTDM Kconfig help section.

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: Andy Gross <andy.gross@linaro.org>