ACPI: add __cpuinit to acpi_processor_add()

Annote acpi_processor_add with cpuinit since it calls a cpuinit function
acpi_processor_power_init and fixes a section mismatch warning.

 We were warned by the following warning:

 LD      drivers/acpi/processor.o
WARNING: drivers/acpi/processor.o(.text+0x1829): Section mismatch in
reference from the function acpi_processor_add() to the function
.cpuinit.text:acpi_processor_power_init()
The function acpi_processor_add() references
the function __cpuinit acpi_processor_power_init().
This is often because acpi_processor_add lacks a __cpuinit
annotation or the annotation of acpi_processor_power_init is wrong.

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>