When using hVHE, we end-up with two TTBRs at EL2. That's great,
but we're not quite ready for this just yet.

Disable TTBR1_EL2 by setting TCR_EL2.EPD1 so that we only
translate via TTBR0_EL2.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230609162200.2024064-12-maz@kernel.orgSigned-off-by: Oliver Upton <oliver.upton@linux.dev>