powerpc: move math-emu over to arch/powerpc

Towards the goal of having arch/powerpc not build anything over in arch/ppc
move math-emu over.  Also, killed some references to arch/ppc/ in the
arch/powerpc Makefile which should belong in drivers/ when the particular
sub-arch's move over to arch/powerpc.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/math-emu/lfs.c

@@ -0,0 +1,37 @@
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <asm/uaccess.h>
+
+#include "soft-fp.h"
+#include "double.h"
+#include "single.h"
+
+int
+lfs(void *frD, void *ea)
+{
+	FP_DECL_D(R);
+	FP_DECL_S(A);
+	float f;
+
+#ifdef DEBUG
+	printk("%s: D %p, ea %p\n", __FUNCTION__, frD, ea);
+#endif
+
+	if (copy_from_user(&f, ea, sizeof(float)))
+		return -EFAULT;
+
+	__FP_UNPACK_S(A, &f);
+
+#ifdef DEBUG
+	printk("A: %ld %lu %ld (%ld) [%08lx]\n", A_s, A_f, A_e, A_c,
+	       *(unsigned long *)&f);
+#endif
+
+	FP_CONV(D, S, 2, 1, R, A);
+
+#ifdef DEBUG
+	printk("R: %ld %lu %lu %ld (%ld)\n", R_s, R_f1, R_f0, R_e, R_c);
+#endif
+
+	return __FP_PACK_D(frD, R);
+}