net: stmmac: fix bad merge conflict resolution

Merge commit 06c54055bebf did a bad conflict resolution accidentally
leaving out a closing brace.  Add it back.

This breaks a handful of defconfigs on ARM, so it'd be good to see it
applied pretty quickly.

Signed-off-by: Olof Johansson <olof@lixom.net>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>