tile: allow disabling CONFIG_EARLY_PRINTK

In that case, any users of early_panic() end up calling panic().
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>

arch/tile/include/asm/setup.h

@@ -25,7 +25,12 @@
 #define MAXMEM_PFN	PFN_DOWN(MAXMEM)
 
 int tile_console_write(const char *buf, int count);
+
+#ifdef CONFIG_EARLY_PRINTK
 void early_panic(const char *fmt, ...);
+#else
+#define early_panic panic
+#endif
 
 /* Init-time routine to do tile-specific per-cpu setup. */
 void setup_cpu(int boot);