Create i945-ivy smm tseg init based on ivy code.

CPU-side logic is unchanged for this range of CPUs as long as all of them
use TSEG (or ASEG, just needs to be consistent). So uplift 206ax code while
extracting southbridge and APIC code into separate functions.

Change-Id: Ib365681d1da8115922c557fddcc59afc156826da
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/10465
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>

src/cpu/intel/smm/gen1/smi.h

@@ -0,0 +1,7 @@
+/* These helpers are for performing SMM relocation. */
+void southbridge_smm_init(void);
+void southbridge_trigger_smi(void);
+void southbridge_clear_smi_status(void);
+void northbridge_get_tseg_base_and_size(u32 *tsegmb, u32 *tseg_size);
+int cpu_get_apic_id_map(int *apic_id_map);
+void northbridge_write_smram(u8 smram);