powerpc/oops: Print the kernel's endian in the oops

Although the MSR tells you what endian you're in it's possible that
isn't the same endian the kernel was built for, and if that happens
you're usually having a very bad day. So print a marker to make
it 100% clear which endian the kernel was built for.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/traps.c

@@ -202,6 +202,12 @@ NOKPROBE_SYMBOL(oops_end);
 static int __die(const char *str, struct pt_regs *regs, long err)
 {
 	printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
+
+	if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN))
+		printk("LE ");
+	else
+		printk("BE ");
+
 #ifdef CONFIG_PREEMPT
 	pr_cont("PREEMPT ");
 #endif