Rename CONFIG_SYS_AUTOLAOD to CONFIG_SYS_DISABLE_AUTOLOAD

The "autoload" environment variable is always checked with env_get_yesno
as it can be set to any form of no.  The default behavior of
env_get_yesno is to return -1 on variables that are not set, which acts
as true in general (we test for non-zero return).  To convert
CONFIG_SYS_AUTOLOAD to Kconfig, given that it was almost always used to
set autoload to no, first rename to CONFIG_SYS_DISABLE_AUTOLOAD for
consistency sake.  Then, make it so that if enabled we set autoload=0 in
the default environment.  Migrate all platforms which set
CONFIG_SYS_AUTOLOAD to non-true or that set autoload to false in their
default environment to using CONFIG_SYS_DISABLE_AUTOLOAD

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/include/configs/octeontx2_common.h b/include/configs/octeontx2_common.h
index 5c75f23..f377ba8 100644
--- a/include/configs/octeontx2_common.h
+++ b/include/configs/octeontx2_common.h
@@ -18,8 +18,7 @@
 /** Extra environment settings */
 #define CONFIG_EXTRA_ENV_SETTINGS	\
 					"loadaddr=20080000\0"	\
-					"ethrotate=yes\0"	\
-					"autoload=0\0"
+					"ethrotate=yes\0"
 
 #define CONFIG_SYS_MMC_MAX_BLK_COUNT	8192