cs8900A and uneven frame lengths

[ksherlock]

In the original VICE code, the received ethernet frame length is rounded up (https://sourceforge.net/p/vice-emu/code/HEAD/tree/trunk/vice/src/arch/shared/rawnetarch_win32.c line 522) so this assert can never happen:

https://github.com/mamedev/mame/blob/d8264ff4e77d9d5d2d8ffa731763b3bb7481f88a/src/devices/machine/cs8900a.cpp#L531

If, for some reason, the cs8900a needs an even sized frame it should probably round it up instead of asserting.

[angelosa]

Current upstream source,, I stopped doing QA here at the copyright holder not being at line 2, definitely legacy territory.