[RFC] main/linux-postmarketos-qcom-msm8992: New port based on 5.14.0-rc1

bullhead boot fixes are in qcom/for-next [1], will be released in v5.15.

I haven't tested other functionality except boot to initramfs, thus adding it as a separate package instead of changing linux-lg-bullhead.

NOTE: this package has not been tested, therefore RFC. Comments are welcome.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux.git/commit/?h=for-next&id=3cb6a271f4b04f11270111638c24fa5c0b846dec