Preliminary VIA Cyrix III emulation

This adds preliminary emulation of the first-gen Samuel core, used in the VIA Cyrix III CPU, at clock speeds from 66 to 700 MHz. This also moves the 440BX emulation out of the dev-branch.

Things working:
- CPUID
- Windows 98SE
- Timings seem identical between WinChip/W2's integer section and this

Things left to do:
- 3DNow on old dynarec
- Half-speed FPU (currently simulated with WinChip 1 timings instead of WinChip 2)

src/machine/m_at_socket8.c

@@ -102,7 +102,7 @@ machine_at_s1668_init(const machine_t *model)
     return ret;
 }
 
-
+#endif
 int
 machine_at_6abx3_init(const machine_t *model)
 {
@@ -131,10 +131,7 @@ machine_at_6abx3_init(const machine_t *model)
     // device_add(&w83977tf_device);
     // device_add(&intel_flash_bxt_device);
     // device_add(&sst_flash_29ee020_device);
-    device_add(&sst_flash_39sf020_device);
+    device_add(&intel_flash_bxt_device);
 
     return ret;
-}
-
-
-#endif
+}