smbios: reorganise OEM strings handling.

OEM strings should not be handled by mobo code but by common code with strings
collected from all devices.

Change-Id: Ibde61a1ca79845670bc0df87dc6c67fa868d48a9
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/6788
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Tested-by: build bot (Jenkins)

src/include/smbios.h

@@ -3,7 +3,6 @@
 
 #include <types.h>
 
-int smbios_write_type11(unsigned long *current, int handle, const char **oem_strings, int count);
 unsigned long smbios_write_tables(unsigned long start);
 int smbios_add_string(char *start, const char *str);
 int smbios_string_table_len(char *start);