parisc: Fix CONFIG_TLB_PTLOCK to work with lightweight spinlock checks

For the TLB_PTLOCK checks we used an optimization to store the spc
register into the spinlock to unlock it. This optimization works as
long as the lightweight spinlock checks (CONFIG_LIGHTWEIGHT_SPINLOCK_CHECK)
aren't enabled, because they really check if the lock word is zero or
__ARCH_SPIN_LOCK_UNLOCKED_VAL and abort with a kernel crash
("Spinlock was trashed") otherwise.

Drop that optimization to make it possible to activate both checks
at the same time.

Noticed-by: Sam James <sam@gentoo.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Tested-by: Sam James <sam@gentoo.org>
Cc: stable@vger.kernel.org # v6.4+
Fixes: 15e64ef6 ("parisc: Add lightweight spinlock checks")