powerpc: Move include files to arch/powerpc/include/asm

from include/asm-powerpc.  This is the result of a

mkdir arch/powerpc/include/asm
git mv include/asm-powerpc/* arch/powerpc/include/asm

Followed by a few documentation/comment fixups and a couple of places
where <asm-powepc/...> was being used explicitly.  Of the latter only
one was outside the arch code and it is a driver only built for powerpc.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/include/asm/serial.h

@@ -0,0 +1,24 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#ifndef _ASM_POWERPC_SERIAL_H
+#define _ASM_POWERPC_SERIAL_H
+
+/*
+ * Serial ports are not listed here, because they are discovered
+ * through the device tree.
+ */
+
+/* Default baud base if not found in device-tree */
+#define BASE_BAUD ( 1843200 / 16 )
+
+#ifdef CONFIG_PPC_UDBG_16550
+extern void find_legacy_serial_ports(void);
+#else
+#define find_legacy_serial_ports()	do { } while (0)
+#endif
+
+#endif /* _PPC64_SERIAL_H */