env: Rename SYS_RELOC_GD_ENV_ADDR to ENV_RELOC_GD_ENV_ADDR

Rename the variable and add ENV_ prefix, so that all configuration
options which are related to environment would have an CONFIG_ENV_
prefix. No functional change.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/common/board_r.c b/common/board_r.c
index 46b5ded..8ee2a47 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -144,7 +144,7 @@
 	 */
 	fixup_cpu();
 #endif
-#ifdef CONFIG_SYS_RELOC_GD_ENV_ADDR
+#ifdef CONFIG_ENV_RELOC_GD_ENV_ADDR
 	/*
 	 * Relocate the early env_addr pointer unless we know it is not inside
 	 * the binary. Some systems need this and for the rest, it doesn't hurt.