msm: sensor: Fix to read the parameters from slave info

Fix to read positions, mode and mount angle from slave info.
If an invalid value is specified in the slave info, default value specified
in the camera dts node will be used.

Change-Id: Id37ccc891bfd2bff48e3c2e9c3242cbe6148d3f7
Signed-off-by: Sureshnaidu Laveti <lsuresh@codeaurora.org>