soc: qcom: Add snapshot of QTI PBS driver

QTI PBS (Programmable Boot Sequence) driver helps triggering
certain PBS on QTI PMICs when available for APPS.

This snapshot is taken as of msm-4.19
commit 9a702c565e5a ("Use 'GPL-2.0-only' as the
SPDX-License-Identifier tag").

Change-Id: I25b6f7cb2bf1cad1413c4389cd2e77e021016b3f
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>