parisc: fix compilation when KEXEC=n and KEXEC_FILE=y

[ Upstream commit e16260c2 ]

Fix compilation when the CONFIG_KEXEC_FILE=y and
CONFIG_KEXEC=n.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>