arm64: Fix EL1/EL2 early init inconsistencies with VHE

When using the Virtualisation Host Extensions, EL1 is not used in
the host and requires no separate configuration.

In addition, with VHE enabled, non-hyp-specific EL2 configuration
that does not need to be done early will be done anyway in
__cpu_setup via the _EL1 system register aliases.  In particular,
the layout and definition of CPTR_EL2 are changed by enabling VHE
so that they resemble CPACR_EL1, so existing code to initialise
CPTR_EL2 becomes architecturally wrong in this case.

This patch simply skips the affected initialisation code in the
non-VHE case.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>