cpufreq: exynos: Remove error return even if no soc is found

This patch helps to have single binary for exynos5440 and previous
exynos soc's. This change is needed for adding exynos5440 cpufreq driver
which does not uses exynos-cpufreq common file and adds it own driver.

Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>