[CPUFREQ] EXYNOS4210: Remove code about bus on cpufreq

This patch removes code for bus on cpufreq because the code
for bus frequency changing moves to busfreq driver.
So code about bus on cpufreq is not necessary.

Signed-off-by: Jaecheol Lee <jc.lee@samsung.com>
Signed-off-by: Jongpill Lee <boyko.lee@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>