arch/powerpc: Simplify some calculations using ARRAY_SIZE() macro.

Replace a number of array length calculations with the ARRAY_SIZE()
macro, for clarity.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/arch/powerpc/cpu/mpc8260/cpu_init.c b/arch/powerpc/cpu/mpc8260/cpu_init.c
index a9bb5ad..55130f7 100644
--- a/arch/powerpc/cpu/mpc8260/cpu_init.c
+++ b/arch/powerpc/cpu/mpc8260/cpu_init.c
@@ -253,7 +253,7 @@
 		RSR_ESRS, "External Soft"}, {
 		RSR_EHRS, "External Hard"}
 	};
-	static int n = sizeof bits / sizeof bits[0];
+	static int n = ARRAY_SIZE(bits);
 	ulong rsr = gd->arch.reset_status;
 	int i;
 	char *sep;