[PATCH v2] serial/pmac_zilog: Remove flawed mitigation for rx irq flood

[Finn Thain]

On Fri, 5 Apr 2024, Michael Ellerman wrote:

> I assume you have tested this on an actual pmac, as well as qemu?
> 

I tested the patched driver and its console functionality using Zilog SCC 
hardware in a Mac IIci, as well as QEMU's q800 virtual machine.

That should suffice from a code coverage point-of-view, since 
pmz_receive_chars() is portable and independent of CONFIG_PPC_PMAC.

Moreover, I don't know how to get my PowerMac G3 to execute the kludge 
that's to be removed here. I can't prove it's impossible, though.