target-arm: Implement vCPU reset via KVM_ARM_VCPU_INIT for 32-bit CPUs

Implement kvm_arm_vcpu_init() as a simple call to arm_arm_vcpu_init()
(which uses the KVM_ARM_VCPU_INIT vcpu ioctl to tell the kernel
to re-initialize the vCPU), rather than via the complicated code
which saves a copy of the register state on first init and then
writes it back to the kernel. This is much simpler and brings the
32-bit KVM code into line with the 64-bit code.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1403802973-20841-1-git-send-email-peter.maydell@linaro.org
