irqchip/irq-mvebu-gicp: Add missing spin_lock init

A spin lock is used in the irq-mvebu-gicp driver, but it is never
initialized. This patch adds the missing spin_lock_init() call in the
driver's probe function.

Fixes: a68a63cb4dfc ("irqchip/irq-mvebu-gicp: Add new driver for Marvell GICP")
Signed-off-by: Antoine Tenart <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Reviewed-by: [e-mail]
Acked-by: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Link: https://lkml.kernel.org/r/[e-mail]

drivers/irqchip/irq-mvebu-gicp.c

···
 		return -ENOMEM;
 
 	gicp->dev = &pdev->dev;
+	spin_lock_init(&gicp->spi_lock);
 
 	gicp->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!gicp->res)