Take out all CPU specific compiler flags and rely on gcc defaults.
The problem on armv7 was that configuring manually armv6 and
using gcc default for thumb tries to build using thumb1 which
does not work. Use Alpine default config for these which is proper
combination.
This makes it possible to provide armv7 as additional architecture in
Alpine, next to armhf. See the discussion in this ML thread:
<https://lists.alpinelinux.org/alpine-devel/6271.html>
It's done by adding armv7 next to armhf in the arch line and also
!armv7 where the arch line said !armhf. The following script was used:
