MIPS: bootm: Fix broken boot_env_legacy codepath

This patch fixes 2 bugs introduced by the following commit

2bb5b638 MIPS: bootm: rework and fix broken bootm code

The CONFIG_IS_ENABLED macro prepends 'CONFIG_' Hence, remove CONFIG_
from CONFIG_MIPS_BOOT_ENV_LEGACY usage.

Also, 2bb5b638 reworks bootm so that linux_env_legacy runs before
linux_cmdline_legacy. However, linux_env_legacy depends on
linux_cmdline_legacy running first as linux_cmdline_init initialilzes
linux_argp which linux_env_legacy later depends on during its
initialization.

Reorder the code so that linux_cmdline_legacy runs before
linux_env_legacy.
Signed-off-by: NZubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>

arch/mips/lib/bootm.c

@@ -279,17 +279,17 @@ static void boot_prep_linux(bootm_headers_t *images)
 		boot_reloc_fdt(images);
 		boot_setup_fdt(images);
 	} else {
-		if (CONFIG_IS_ENABLED(CONFIG_MIPS_BOOT_ENV_LEGACY))
-			linux_env_legacy(images);
-
 		if (CONFIG_IS_ENABLED(MIPS_BOOT_CMDLINE_LEGACY)) {
 			linux_cmdline_legacy(images);
 
-			if (!CONFIG_IS_ENABLED(CONFIG_MIPS_BOOT_ENV_LEGACY))
+			if (!CONFIG_IS_ENABLED(MIPS_BOOT_ENV_LEGACY))
 				linux_cmdline_append(images);
 
 			linux_cmdline_dump();
 		}
+
+		if (CONFIG_IS_ENABLED(MIPS_BOOT_ENV_LEGACY))
+			linux_env_legacy(images);
 	}
 }