Add standard C headers to fix build on some systems after xf86_ansic.h removal.

This appears to have been hidden for others by header pollution in X Server
headers.

src/i830_bios.c

@@ -29,6 +29,9 @@
 #undef VERSION	/* XXX edid.h has a VERSION too */
 #endif
 
+#include <stdio.h>
+#include <string.h>
+
 #define _PARSE_EDID_
 #include "xf86.h"
 #include "i830.h"

src/i830_display.c

@@ -31,6 +31,10 @@
 #endif
 
 #include <unistd.h>
+#include <string.h>
+#include <assert.h>
+#include <stdlib.h>
+#include <math.h>
 
 #include "xf86.h"
 #include "i830.h"

src/i830_sdvo.c

@@ -26,6 +26,9 @@ USE OR OTHER DEALINGS IN THE SOFTWARE.
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
+
+#include <string.h>
+
 #include "xf86.h"
 #include "xf86_OSproc.h"
 #include "compiler.h"