ARM: shmobile: r8a7778: Make r8a7778_init_irq_dt() static

As of commit 4baadb9e ("ARM: shmobile: r8a7778: remove obsolete
setup code"), r8a7778_init_irq_dt() is no longer used outside
setup-r8a7778.c.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/mach-shmobile/setup-r8a7778.c

@@ -42,7 +42,8 @@ static void __init r8a7778_timer_init(void)
 
 #define INT2NTSR0	0x00018 /* 0xfe700018 */
 #define INT2NTSR1	0x0002c /* 0xfe70002c */
-void __init r8a7778_init_irq_dt(void)
+
+static void __init r8a7778_init_irq_dt(void)
 {
 	void __iomem *base = ioremap_nocache(0xfe700000, 0x00100000);