cpufrequtils: Create proper symlinks to versioned library

Currently it produces duplicated .so files for .so.0 and .so.0.0.0
this is also noticed by opkg upgrade

Configuring libxcb-randr0.
/sbin/ldconfig: /usr/lib/libcpufreq.so.0 is not a symbolic link

Additionally helps in some code size savings

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>