The armdiv array may contain unset divider values.
Check the relevant value to prevent division by zero
errors. Also check for set nr_armdiv and armdivmask
before meddling with clkdiv0.
Signed-off-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>