sim-se: Set ArmProcess64 hwcaps depending on ID regs

sim-se: Set ArmProcess64 hwcaps depending on ID regs

ArmProcess64 needs to query AArch64 ID registers to check which hw
capability is going to report in the appropriate aux vector's entry.

Change-Id: I1e1294b831e902226f9b162f25e841e53b940454
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/13164
Reviewed-by: Brandon Potter <Brandon.Potter@amd.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>