irqchip/gic-v4.1: Use readx_poll_timeout_atomic() to fix sleep in atomic

readx_poll_timeout() can sleep if @sleep_us is specified by the caller,
and is therefore unsafe to be used inside the atomic context, which is
this case when we use it to poll the GICR_VPENDBASER.Dirty bit in
irq_set_vcpu_affinity() callback.

Let's convert to its atomic version instead which helps to get the v4.1
board back to life!

Fixes: 96806229 ("irqchip/gic-v4.1: Add support for VPENDBASER's Dirty+Valid signaling")
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200605052345.1494-1-yuzenghui@huawei.com

drivers/irqchip/irq-gic-v3-its.c

@@ -3797,7 +3797,7 @@ static void its_wait_vpt_parse_complete(void)
 	if (!gic_rdists->has_vpend_valid_dirty)
 		return;
 
-	WARN_ON_ONCE(readq_relaxed_poll_timeout(vlpi_base + GICR_VPENDBASER,
+	WARN_ON_ONCE(readq_relaxed_poll_timeout_atomic(vlpi_base + GICR_VPENDBASER,
 						       val,
 						       !(val & GICR_VPENDBASER_Dirty),
 						       10, 500));