ARM: shmobile: Remove partial CPU Hotplug from EMEV2

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: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>