v8.4 stable AGNi for MIATOLL excalibur/curtana/joyeuse/gram

Merge kernel 4.14.223, 4.14.224, 4.14.225
AGNi sound mod v2.4 with HiFi audio mode.
Introducing MIUI A11 support.
Merge CAF LA.UM.9.1.r1-09100-SMxxx0.0 (AOSP & MIUI R)
qcacld-3.0: Merge wifi CAF LA.UM.9.1.r1-09100-SMxxx0.0 (AOSP & MIUI R)
ion: Implement ion heap pool auto refill + more updates
treewide: get rid of various variable length arrays.
alarmtimer: Add ndelay for tight loop
add devfreq boost and its requirements.
A ton of updates to iommu, tcp-bbr, kgsl, EAS-task scheduler and lots more.

Detailed Changelog:
changelog.txt