ARM: dts: msm: Add debug uart support for mdmfermium

As per the new schematic debug uart got changed. Configure
BLSP1UART5 as debug uart rather than using BLSP1UART2.

Change-Id: If256dceff5c114d41e9de04861577d8c5b5cd614
Signed-off-by: Venkatesh Yadav Abbarapu <vabbar@codeaurora.org>