cpufreq: ppc-corenet-cpufreq: Fix __udivdi3 modpost error

bfa709bc (cpufreq: powerpc: add cpufreq
transition latency for FSL e500mc SoCs) introduced a modpost error:

ERROR: "__udivdi3" [drivers/cpufreq/ppc-corenet-cpufreq.ko] undefined!
make[1]: *** [__modpost] Error 1

Fix this by avoiding 64 bit integer division.

gcc version 4.8.2

Fixes: bfa709bc (cpufreq: powerpc: add cpufreq transition latency for FSL e500mc SoCs)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>