ARM: 7639/1: cache-l2x0: add missed dummy outer_resume entry

Commit 91c2ebb9 (ARM: 7114/1: cache-l2x0: add resume entry for l2
in secure mode) added resume entry for l2 in secure mode, but it missed
the dummy entry when CONFIG_CACHE_L2X0 is not set.

(Commit text edited by rmk.)

Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>