kconfig: remove unneeded U-Boot extension code

This code was introduced to support the multiple .config
configuration in U-Boot.  We do not need it any more.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

scripts/kconfig/confdata.c

@@ -951,14 +951,6 @@ int conf_write_autoconf(void)
 	FILE *out, *tristate, *out_h;
 	int i;
 
-	/*
-	 * Added for U-Boot SPL/TPL
-	 */
-	name = getenv("KCONFIG_OBJDIR");
-	if (name && name[0])
-		if (chdir(name))
-			return 1;
-
 	sym_clear_all_valid();
 
 	file_write_dep("include/config/auto.conf.cmd");