armhf package contains x86_64 binaries

After using the steps and workaround from #1229 (closed):

The linux-postmarketos-stable-dev package gets correctly built and I get the package armhf/linux-postmarketos-stable-dev-r1.apk in my cache. But the binaries in this package are actually x86_64 instead of armhf.

You can verify this by running

$ objdump -x scripts/basic/fixdep
fixdep:     file format elf64-x86-64
fixdep
architecture: i386:x86-64, flags 0x00000150:
HAS_SYMS, DYNAMIC, D_PAGED
...

This is probably caused by #1228