arm:remove hardcoded base address for the in kernel serial.

Removed hardcoded base address for in kernel serial. This will ease
porting to different boards and allow us to remap i/o at later stage.

Change-Id: I4a4e00ed2aa2f94dfe928dc43a6816d3b94576b7

kernel/main.c

@@ -127,6 +127,10 @@ void kmain(kinfo_t *local_cbi)
   memcpy(&kinfo, local_cbi, sizeof(kinfo));
   memcpy(&kmess, kinfo.kmess, sizeof(kmess));
 
+#ifdef __arm__
+  /* We want to initialize serial before we do any output */
+  omap3_ser_init();
+#endif
   /* We can talk now */
   printf("MINIX booting\n");