dt-bindings: qcom: qpnp-fg-gen4: Add snapshot

Add snapshot of the dt-bindings of the qpnp-fg-gen4 driver as of
msm-4.14 'commit 7e16ff6cdde5 ("defconfig: qcs405: enable WLAN configs
for 32-bit QCS405")'.

Change-Id: I4113f0736ca44f09a9d73656d84b3ff015a2bf26
Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>