spl: spl_legacy: Use IS_ENABLED() to remove #ifdef

Use IS_ENABLED() instead of #ifdef CONFIG_ to remove one #ifdef.

No functional change intended.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
1 file changed