ppc: Various minor compile fixes

This fixes up a variety of minor problems in compiling with ARCH=ppc
arising from using the merged versions of various header files.
A lot of the changes are just adding #include <asm/machdep.h> to
files that use ppc_md or smp_ops_t.

This also arranges for us to use semaphore.c, vecemu.c, vector.S and
fpu.S from arch/powerpc/kernel when compiling with ARCH=ppc.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/ppc/syslib/ppc4xx_pic.c b/arch/ppc/syslib/ppc4xx_pic.c
index 4008621..0b43563 100644
--- a/arch/ppc/syslib/ppc4xx_pic.c
+++ b/arch/ppc/syslib/ppc4xx_pic.c
@@ -25,6 +25,7 @@
 #include <asm/system.h>
 #include <asm/irq.h>
 #include <asm/ppc4xx_pic.h>
+#include <asm/machdep.h>
 
 /* See comment in include/arch-ppc/ppc4xx_pic.h
  * for more info about these two variables