env: Rename common functions related to setenv()

We are now using an env_ prefix for environment functions. Rename these
commonly used functions, for consistency. Also add function comments in
common.h.

Suggested-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/autoboot.c b/common/autoboot.c
index c52bad8..41f1820 100644
--- a/common/autoboot.c
+++ b/common/autoboot.c
@@ -278,12 +278,12 @@
 	/* Add an env variable to point to a kernel payload, if available */
 	addr = fdtdec_get_config_int(gd->fdt_blob, "kernel-offset", 0);
 	if (addr)
-		setenv_addr("kernaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
+		env_set_addr("kernaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
 
 	/* Add an env variable to point to a root disk, if available */
 	addr = fdtdec_get_config_int(gd->fdt_blob, "rootdisk-offset", 0);
 	if (addr)
-		setenv_addr("rootaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
+		env_set_addr("rootaddr", (void *)(CONFIG_SYS_TEXT_BASE + addr));
 #endif /* CONFIG_OF_CONTROL && CONFIG_SYS_TEXT_BASE */
 }
 
@@ -300,7 +300,7 @@
 	bootcount = bootcount_load();
 	bootcount++;
 	bootcount_store(bootcount);
-	setenv_ulong("bootcount", bootcount);
+	env_set_ulong("bootcount", bootcount);
 	bootlimit = getenv_ulong("bootlimit", 10, 0);
 #endif /* CONFIG_BOOTCOUNT_LIMIT */