ARM: dts: msm: Change pinctrl settings for BLSP1 UART3 for msmcobalt

Modify the sleep state settings for BLSP1 UART3 pins to optimize power
when the usecase isn't in play.

Change-Id: I1405a8561b1ecb2e3da87ed8b26fb087433a1c11
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>