irqchip/sg2042-msi: Fix wrong type cast in sg2044_msi_irq_ack()

The type cast in sg2044_msi_irq_ack() lost the __iomem attribute, which
makes the pointer type incorrect.

Add it back.

Fixes: e96b93a ("irqchip/sg2042-msi: Add the Sophgo SG2044 MSI interrupt controller")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Chen Wang <unicorn_wang@outlook.com>
Link: https://lore.kernel.org/all/20250422003804.214264-1-inochiama@gmail.com
Closes: https://lore.kernel.org/oe-kbuild-all/202504211251.B3aesulq-lkp@intel.com/

Author: inochisa

drivers/irqchip/irq-sg2042-msi.c

@@ -98,7 +98,7 @@ static void sg2044_msi_irq_ack(struct irq_data *d)
 {
 	struct sg204x_msi_chipdata *data = irq_data_get_irq_chip_data(d);
 
-	writel(0, (u32 *)data->reg_clr + d->hwirq);
+	writel(0, (u32 __iomem *)data->reg_clr + d->hwirq);
 	irq_chip_ack_parent(d);
 }