Fix race condition in option_table.h generation by moving the include statement
to those files that actually need it. This significantly reduces the number of
dependencies, so it's no longer extremely ugly to specify them manually (see 
the src/pc80/Makefile.inc portion)
Also, drop the AMD DBM690T work around for the issue.

Signed-off-by: Stefan Reinauer <stepan@coresystems.de>

Index: src/include/pc80/mc146818rtc.h
===================================================================
--- src/include/pc80/mc146818rtc.h	(revision 5761)
+++ src/include/pc80/mc146818rtc.h	(working copy)
@@ -81,14 +81,6 @@
 #define PC_CKS_RANGE_END	45
 #define PC_CKS_LOC		46
 
-/* coreboot cmos checksum is usually only built over bytes 49..125
- * LB_CKS_RANGE_START, LB_CKS_RANGE_END and LB_CKS_LOC are defined
- * in option_table.h
- */
-#if CONFIG_HAVE_OPTION_TABLE
-#include <option_table.h>
-#endif
-
 #ifndef UTIL_BUILD_OPTION_TABLE
 #include <arch/io.h>
 static inline unsigned char cmos_read(unsigned char addr)
Index: src/mainboard/amd/dbm690t/Kconfig
===================================================================
--- src/mainboard/amd/dbm690t/Kconfig	(revision 5761)
+++ src/mainboard/amd/dbm690t/Kconfig	(working copy)
@@ -25,12 +25,6 @@
 	string
 	default amd/dbm690t
 
-# This is a temporary fix, and should be removed when the race condition for
-# building option_table.h is fixed.
-config WARNINGS_ARE_ERRORS
-	bool
-	default n
-
 config DCACHE_RAM_BASE
 	hex
 	default 0xc8000
Index: src/pc80/mc146818rtc_early.c
===================================================================
--- src/pc80/mc146818rtc_early.c	(revision 5761)
+++ src/pc80/mc146818rtc_early.c	(working copy)
@@ -1,6 +1,10 @@
 #include <pc80/mc146818rtc.h>
 #include <fallback.h>
 
+#if CONFIG_USE_OPTION_TABLE
+#include <option_table.h>
+#endif
+
 #ifndef CONFIG_MAX_REBOOT_CNT
 #error "CONFIG_MAX_REBOOT_CNT not defined"
 #endif
Index: src/pc80/Makefile.inc
===================================================================
--- src/pc80/Makefile.inc	(revision 5761)
+++ src/pc80/Makefile.inc	(working copy)
@@ -8,3 +8,4 @@
 subdirs-y += vga
 
 $(obj)/pc80/mc146818rtc.o : $(OPTION_TABLE_H)
+$(obj)/pc80/mc146818rtc_early.initobj.o : $(OPTION_TABLE_H)
Index: src/pc80/mc146818rtc.c
===================================================================
--- src/pc80/mc146818rtc.c	(revision 5761)
+++ src/pc80/mc146818rtc.c	(working copy)
@@ -2,6 +2,9 @@
 #include <pc80/mc146818rtc.h>
 #include <boot/coreboot_tables.h>
 #include <string.h>
+#if CONFIG_USE_OPTION_TABLE
+#include <option_table.h>
+#endif
 
 /* control registers - Moto names
  */