powerpc: Remove STRICT_KERNEL_RWX incompatibility with RELOCATABLE

[ Upstream commit c55d7b5e64265fdca45c85b639013e770bde2d0e ]

I have tested this with the Radix MMU and everything seems to work, and
the previous patch for Hash seems to fix everything too.
STRICT_KERNEL_RWX should still be disabled by default for now.

Please test STRICT_KERNEL_RWX + RELOCATABLE!

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191224064126.183670-2-ruscur@russell.cc


Signed-off-by: Sasha Levin <sashal@kernel.org>