backlight: qcom-spmi-wled: Add support for PM7325B WLED

Add new compatible string for PM7325B WLED. Add support to read
battery resistance, current and OCV from battery charger driver
through glink based interface.

Change-Id: I421c4225862c4f72f00dff14214b1b613c93fa42
Signed-off-by: Jishnu Prakash <jprakash@codeaurora.org>