soc: qcom: Add irq clear handling during SE init

when the kernel inits a SE, its quite possible we have pending interrupts
from bootloaders which did not handle/clear them. So do this in kernel at
the SE init, to avoid some of it causing bad behavior, while at it also
club all the register writes needed to clear the se irqs into a function
to avoid repeating it over.

Signed-off-by: Alok Chauhan <alokc@codeaurora.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>