backlight: qcom-spmi-wled: Update flash sink config in auto calibration

Currently, when the sink configuration is incorrect, auto
calibration fixes the sink configuration dynamically. However,
WLED flash sink configuration is not updated accordingly. This
can cause OVP faults whenever the selfie flash is attempted. Fix
it by updating WLED flash sink configuration in auto calibration.

Since the auto calibration can be run during HW initialization
before flash configuration is made, move wled_flash_setup() to
wled5_setup().

Change-Id: I953a59fd4e053390c382ce9e27ba2fa76cc4f5c1
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>