community/linux-postmarketos-mediatek-mt8173: upgrade to 6.6.2 and enable CONFIG_LRU_GEN

I obtained one of these Chromebooks this weekend and thought it would be nice to get the kernel up to date.

Reading discussion in https://gitlab.com/postmarketOS/pmaports/-/merge_requests/4264 I thought it a good idea to add the CONFIG_LRU_GEN option too. It boots and works on my Lenovo C330, same as the 6.4.4 kernel did. The kconfig changes are just pmbootstrap kconfig update and accepting all default values.

Tested wi-fi, sound, suspend+resume, FDE w/unl0kr, touchscreen, video playback. The laptop works basically exactly like it did with 6.4.4, but I've only had it for a day anyway, and this kernel applies to many devices, so I'm likely missing something.