x86: rename mpc_config_processor to mpc_cpu

Impact: cleanup, solve 80 columns wrap problems

mpc_config_processor should be renamed to mpc_cpu.

The reason: the 'c' in MPC already means 'config' -
no need to repeat that in the type name.

Plus 'processor' is a lot longer than 'cpu' - so we try to use 'cpu' in all
type names, as much as possible.

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>