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/kernel/head.S b/arch/ppc/kernel/head.S
index 2c3a1d3..5b43987 100644
--- a/arch/ppc/kernel/head.S
+++ b/arch/ppc/kernel/head.S
@@ -467,7 +467,7 @@
 	EXCEPTION_PROLOG
 	bne	load_up_fpu		/* if from user, just load it up */
 	addi	r3,r1,STACK_FRAME_OVERHEAD
-	EXC_XFER_EE_LITE(0x800, KernelFP)
+	EXC_XFER_EE_LITE(0x800, kernel_fp_unavailable_exception)
 
 /* Decrementer */
 	EXCEPTION(0x900, Decrementer, timer_interrupt, EXC_XFER_LITE)