soc: qcom: service-locator: Add soft-dependency on QRTR

QRTR needs to be functional before service locator is up. Hence,
add a soft-dependency on the QRTR to ensure this happens when
these drivers are built as modules.

Change-Id: I1919ffc03f8eb215c21724a46c1250787ba2067c
Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>