env: Move env_get() to env.h

Move env_get() over to the new header file.

Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Simon Glass <sjg@chromium.org>

env/callback.c

@@ -5,6 +5,7 @@
  */
 
 #include <common.h>
+#include <env.h>
 #include <environment.h>
 
 #if defined(CONFIG_NEEDS_MANUAL_RELOC)

env/eeprom.c

@@ -9,6 +9,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <env.h>
 #include <environment.h>
 #include <linux/stddef.h>
 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)

env/nvram.c

@@ -25,6 +25,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <env.h>
 #include <environment.h>
 #include <linux/stddef.h>
 #include <search.h>