ath79 subtarget with cmdline from bootloader

[SAn]

Hi! 

The LibreRouter uses a dual-boot scheme that relies on the bootloader configuring the kernel cmdline. At ar71xx 18.06 it was possible to select per device if the cmdline from the bootloader has to be honored (using patch-cmdline).
AFAIK there is no such possibility on ath79.

Would you consider accepting a patch that adds a new ath79 subtarget with CONFIG_MIPS_CMDLINE_FROM_BOOTLOADER (or CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND)?

It would be valuable for the people using LibreRouter devices to be able to use official OpenWrt 20.xx images with the dual-boot support. Currently there are multiple mips targets that use CONFIG_MIPS_CMDLINE_FROM_BOOTLOADER (bcm47xx, octeon, malta, and a few more).

Best!
SAn