irqchip/gic-v3: Make distributor priorities variables

irqchip/gic-v3: Make distributor priorities variables

In subsequent patches the GICv3 driver will choose the regular interrupt
priority at boot time.

In preparation for using dynamic priorities, place the priorities in
variables and update the code to pass these as parameters. Users of
GICD_INT_DEF_PRI_X4 are modified to replicate the priority byte using
REPEAT_BYTE_U32().

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240617111841.2529370-4-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>