dt-bindings: remoteproc: qcom: Add Q6v5 Modem PIL binding for MSM8998

Add new compatible string for Qualcomm MSM8998 SoCs.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>