FP2: Tweak performance-related kernel configs

The goal is to reduce overall "sluggishness" of the FP2 on Android 9.

Changes are partially taken over from the LineageOS FP2 kernel. Disable
a few debug configs, disable most CGROUP and CPUSET configs, switch
iosched to CFQ, use LZMA to compress the kernel. On userdebug builds
(fairphone_defconfig), keep some of the debug configs active.

Issue: FP2P-132
Change-Id: Ib69689fe7877333b2c4078c099b9c6ffcbe4e337
2 files changed