Removing 5.4 support for bcm27xx and bcm53xx

[Rafał Miłecki]

On 2021-10-02 18:43, Adrian Schmutzler wrote:
> both bcm27xx and bcm53xx have kernel 5.10 by default for more than one
> month.
> 
> I'd like to remove 5.4 patches etc. there, so we don't have to bother 
> with
> 5.4 for new patches (like stintel had to when adding config symbols
> recently).

bcm53xx + 5.10 is still broken for EA9500 and Tenda AC-9. Having 5.4 is 
useful for debugging. I'd prefer to wait a moment before we drop it.