Now that all of the GSI interrupts are handled uniformly,
change gsi_irq_type_update() so it takes a value.  Have the
function assign that value to the cached mask of enabled GSI
IRQ types before writing it to hardware.

Note that gsi_irq_teardown() will only be called after
gsi_irq_disable(), so it's not necessary for the former
to disable all IRQ types.  Get rid of that.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>