spl: env_common.c: make CONFIG_SPL_BUILD contain function env_import

The functionality env_import will be used in the SPL. They
had been excluded by ifndef CONFIG_SPL_BUILD. Now, put it
into the SPL.

Signed-off-by: Ying Zhang <b40530@freescale.com>
Acked-by: Tom Rini <trini@ti.com>
Acked-by: York Sun <yorksun@freescale.com>

common/env_common.c

@@ -140,7 +140,6 @@ int set_default_vars(int nvars, char * const vars[])
 				H_NOCLEAR | H_INTERACTIVE, nvars, vars);
 }
 
-#ifndef CONFIG_SPL_BUILD
 /*
  * Check if CRC is valid and (if yes) import the environment.
  * Note that "buf" may or may not be aligned.
@@ -172,7 +171,6 @@ int env_import(const char *buf, int check)
 
 	return 0;
 }
-#endif
 
 void env_relocate(void)
 {