ARM: virt: Avoid bx instruction for compatibility with <=ARMv4

ARM: virt: Avoid bx instruction for compatibility with <=ARMv4

commit a4a12e008e292a81d312659529b71be2026ab355 upstream.

Non-T variants of ARMv4 do not support the bx instruction.

However, __hyp_stub_install is always called from the same
instruction set used to build the bulk of the kernel, so bx should
not be necessary.

This patch uses the traditional "mov pc" instead of bx.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
[will: fixed up remaining bx instruction]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>