The 0001-Enable-uart3-for-NanoPi-Neo-Air-used-by-BT.patch fails to
apply over the 4.19.76 mainline kernel, so remove it and apply a
reworked version of it.
Add the correct path for the patches directory, linux-mainline-4.19
instead of linux-4.19 (removed in a previous commit and all it's
content has been placed in linux-mainline-4.19).
Signed-off-by: Vicentiu Galanopulo <vicentiu@balena.io>
