msm: krait-regulator: Stage power-on of BHS switches in APC_PWR_GATE_CTL

BHS_EN and the BHS_SEG_EN bits should not be set in the same register
write. Separate them by 1us to throttle inrush current into the core
and avoid potential disruptions on the shared Krait power rail.

Change-Id: I52b7b3e33e870b9ea4c5b35e7892bb699acb53da
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>