irqchip/gic-v3-its: Use full range of LPIs

As we used to represent the LPI range using a bitmap, we were reducing
the number of LPIs to at most 64k in order to preserve memory.

With our new allocator, there is no such need, as dealing with 2^16
or 2^32 LPIs takes the same amount of memory.

So let's use the number of IntID bits reported by the GIC instead of
an arbitrary limit.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

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

@@ -1445,7 +1445,6 @@ static struct irq_chip its_irq_chip = {
  */
 #define IRQS_PER_CHUNK_SHIFT	5
 #define IRQS_PER_CHUNK		(1UL << IRQS_PER_CHUNK_SHIFT)
-#define ITS_MAX_LPI_NRBITS	16 /* 64K LPIs */
 
 static DEFINE_MUTEX(lpi_range_lock);
 static LIST_HEAD(lpi_range_list);
@@ -1626,7 +1625,7 @@ static int __init its_alloc_lpi_tables(void)
 {
 	phys_addr_t paddr;
 
-	lpi_id_bits = min_t(u32, gic_rdists->id_bits, ITS_MAX_LPI_NRBITS);
+	lpi_id_bits = gic_rdists->id_bits;
 	gic_rdists->prop_page = its_allocate_prop_table(GFP_NOWAIT);
 	if (!gic_rdists->prop_page) {
 		pr_err("Failed to allocate PROPBASE\n");