Remove partial CPU hotplug support from EMEV2 SMP code.

The upstream EMEV2 SMP support code has no CPU shutdown or
reset ability so we cannot reboot the secondary CPU cores.

Regular SMP operation is however still working as expected.
Signed-off-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>