arm64: mm: Temporarily disable ARM64_SW_TTBR0_PAN

arm64: mm: Temporarily disable ARM64_SW_TTBR0_PAN

BugLink: http://bugs.launchpad.net/bugs/1751064
Commit 376133b7edc2 upstream.

We're about to rework the way ASIDs are allocated, switch_mm is
implemented and low-level kernel entry/exit is handled, so keep the
ARM64_SW_TTBR0_PAN code out of the way whilst we do the heavy lifting.

It will be re-enabled in a subsequent patch.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>