soc: qcom: pil-q6v5: Update cx_max to INT_MAX while voting for CX rail

To support a higher GPU frequency on MSM8937 Pro target the CX rail
expects TURBO_HIGH voltage level. So while requesting regulator voltage
for CX rail request with max value set as INT_MAX.

Change-Id: I47eb863c4b384bb12e2ff21c44104847b0baa7ee
Signed-off-by: Avaneesh Kumar Dwivedi <akdwived@codeaurora.org>