dt-bindings: qpnp-fg-gen4: Support configure skew in capacity learning

Capacity learning algorithm takes in a parameter to configure
skew if when specified by the user to offset the errors that
can be accumulated based on the charging nature. Add a device
tree parameter "qcom,cl-skew" to configure it.

Change-Id: I58fcc3f62007fc9c75e8c5f1d2469e1cbd183764
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>