target/arm: Implement RAZ/WI HACTLR2

target/arm: Implement RAZ/WI HACTLR2

The v8 AArch32 HACTLR2 register maps to bits [63:32] of ACTLR_EL2.
We implement ACTLR_EL2 as RAZ/WI, so make HACTLR2 also RAZ/WI.
(We put the regdef next to ACTLR_EL2 as a reminder in case we
ever make ACTLR_EL2 something other than RAZ/WI).

Signed-off-by: Peter Maydell <[email protected]>
Reviewed-by: Richard Henderson <[email protected]>
Reviewed-by: Edgar E. Iglesias <[email protected]>
Reviewed-by: Luc Michel <[email protected]>
Message-id: 20180820153020[email protected]