ARM: tegra: simplify halt_avp()

ARM: tegra: simplify halt_avp()

In order to completely halt the AVP processor, we should simply write
FLOW_MODE_STOP without any extra options that allow wakeup. Amend the
code to do this.

I believe that enabling FIQ_1 and IRQ_1 allow the CPU to be awoken by
interrupts. We don't want this; if later SW wishes to use the AVP, it
should be reset and booted from scratch.

Related, the bits that were previously IRQ_1 and FIQ_1 have a slightly
different definition starting with Tegra114, so the values we're
writing don't entirely make sense there anyway.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>