ARM: zynq: use physical cpuid in zynq_slcr_cpu_stop/start

When kernel booting, it will create a cpuid map between the logical cpus
and physical cpus. In a normal boot, the cpuid map is as below:

    Physical      Logical
        0    ==>     0
        1    ==>     1

But in kdump, there is a condition that the crash happens at the
physical cpu1, and the crash kernel will run at the physical cpu1 too,
so the cpuid map in crash kernel is as below:

    Physical      Logical
        1    ==>     0
        0    ==>     1

The functions zynq_slcr_cpu_stop/start is to stop/start the physical
cpus, the parameter cpu should be the physical cpuid. So use
cpu_logical_map to translate the logical cpuid to physical cpuid.
Or else the logical cpu0(physical cpu1) will stop itself and
the processor will hang.

Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>