arm: Guests can trigger a deadlock on Cortex-A77

Cortex-A77 cores (r0p0 and r1p0) are affected by erratum 1508412

where software, under certain circumstances, could deadlock a core

due to the execution of either a load to device or non-cacheable memory,

and either a store exclusive or register read of the Physical

Address Register (PAR_EL1) in close proximity.