Revamp Intel microcode update code

- add GPLv2 + copyright header after talking to Ron
- "bits" in struct microcode served no real purpose but
  getting its address taken. Hence drop it
- use asm volatile instead of __asm__ volatile
- drop superfluous wrmsr (that seems to be harmless but
  is still wrong) in read_microcode_rev
- use u32 instead of unsigned int where appropriate
- make code usable both in bootblock and in ramstage
- drop ROMCC style print_debug statements
- drop microcode update copy in Sandybridge bootblock

Change-Id: Iec4d5c7bfac210194caf577e8d72446e6dfb4b86
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/928
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/include/cpu/intel/microcode.h

@@ -1 +1,22 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2000 Ronald G. Minnich
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#if !defined(__ROMCC__)
 void intel_update_microcode(const void *microcode_updates);
+#endif