prebuilt: update build scripts.

Everything is now built in <kerneldir>/Packages/

Change-Id: Ie523b81995b5cfaea5ab35049137628801061eb2
holiday: lower adsp heap size to fix graphical glitches

Change-Id: I5a79967cee48a0d56695c0f8be4e79f408c9c137
holiday: set adsp2 heap size to 0.

After some testing, i can't find any negative impact by having no adsp2
heap. Will revert if it causes problems

Change-Id: Id5513a44830f2578aff864a110263f1000d6b90b