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>

arch/ppc/platforms/gemini_setup.c

@@ -36,6 +36,7 @@
 #include <asm/time.h>
 #include <asm/open_pic.h>
 #include <asm/bootinfo.h>
+#include <asm/machdep.h>
 
 void gemini_find_bridges(void);
 static int gemini_get_clock_speed(void);