xpl: Rename spl_phase_prefix() and spl_phase_name()

Use simpler names for these functions.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/lib/tpl.c b/arch/x86/lib/tpl.c
index 0606b4a..f7df7e0 100644
--- a/arch/x86/lib/tpl.c
+++ b/arch/x86/lib/tpl.c
@@ -103,7 +103,7 @@
 
 void __noreturn jump_to_image_no_args(struct spl_image_info *spl_image)
 {
-	debug("Jumping to %s at %lx\n", spl_phase_name(xpl_next_phase()),
+	debug("Jumping to %s at %lx\n", xpl_name(xpl_next_phase()),
 	      (ulong)spl_image->entry_point);
 #ifdef DEBUG
 	print_buffer(spl_image->entry_point, (void *)spl_image->entry_point, 1,