global: Avoid indirect inclusion of <env.h> from <command.h>

The include file <command.h> does not need anything from <env.h>.
Furthermore, include/env.h itself includes other headers which can lead
to longer indirect inclusion paths. To prepare to remove <env.h> from
<command.h> fix all of the places which had relied on this indirect
inclusion to instead include <env.h> directly.

Reviewed-by: Mattijs Korpershoek <mkorpershoek@kernel.org> # android, bcb
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org> # spawn
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/cmd/adc.c b/cmd/adc.c
index 4d3b5b6..334ba7f 100644
--- a/cmd/adc.c
+++ b/cmd/adc.c
@@ -5,6 +5,7 @@
  */
 #include <command.h>
 #include <dm.h>
+#include <env.h>
 #include <adc.h>
 #include <linux/printk.h>