cpufreq: Do away with sibling policy sharing

Messed with sched & mpdecision by waking up cpu1 needlessly on occasion.

Squashed revert of the following:

Revert "cpufreq: slightly more robust cpu0/1 policy matching code"

This reverts commit 07c41c242db61552668fdb718b0e6c4095442d76.

Revert "cpufreq: force cpu1 policy to match cpu0 when changing freq or gov"

This reverts commit e75f576de1e31634cce776f8861e50258ed83cda.

Revert "cpufreq: enable sibling cpu policy sharing"

This reverts commit 254b4f1216327909cbb02e0283b4a9e29e081d7c.