Update README for RPi 1 & RPi 1B

[juadde]

Hello @liske,

I managed to get needrestart working on RPi 1 and 1B also with a workaround.
I felt like I could share my findings (fix is very much straightforward).

I hope you can merge this to your README to help others.

Thanks for this great tool.

Kind regards.

[liske]

Thanks!