ARM: 8758/1: decompressor: restore r1 and r2 just before jumping to the kernel

The hypervisor setup before __enter_kernel destroys the value
sotred in r1. The value needs to be restored just before the jump.

Fixes: 6b52f7bd ("ARM: hyp-stub: Use r1 for the soft-restart address")
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>