irqchip/sg2042-msi: Add missing chip flags

The sg2042-msi driver uses the fallback callbacks set by
msi_lib_init_dev_msi_info(). commit 1c000dc ("irqchip/irq-msi-lib:
Optionally set default irq_eoi()/irq_ack()") changed the behavior of the
fallback mechanism by making it opt-in.

The sg2042-msi was not fixed up for this, which causes a NULL pointer
dereference due to the missing irq_ack() callback.

Add the missing chip flag to msi_parent_ops.

Fixes: c667415 ("irqchip: Add the Sophgo SG2042 MSI interrupt controller")
Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250217085657.789309-3-apatel@ventanamicro.com
Link: https://lore.kernel.org/all/20250405055625.1530180-1-inochiama@gmail.com

drivers/irqchip/irq-sg2042-msi.c

@@ -151,6 +151,7 @@ static const struct irq_domain_ops sg2042_msi_middle_domain_ops = {
 static const struct msi_parent_ops sg2042_msi_parent_ops = {
 	.required_flags		= SG2042_MSI_FLAGS_REQUIRED,
 	.supported_flags	= SG2042_MSI_FLAGS_SUPPORTED,
+	.chip_flags		= MSI_CHIP_FLAG_SET_ACK,
 	.bus_select_mask	= MATCH_PCI_MSI,
 	.bus_select_token	= DOMAIN_BUS_NEXUS,
 	.prefix			= "SG2042-",