configs/qemu_arm_ebbr: linux needs host-openssl

configs/qemu_arm_ebbr: linux needs host-openssl

The kernel build needs host-openssl; add it to the configuration.

In practice the documented build recipe works fine and the build failures
can only be seen with highly parallel builds using per-package directories.

This fixes the following compilation error:

  certs/extract-cert.c:21:10: fatal error: openssl/bio.h: No such file or directory

Fixes: 7115ab39189a6c660745267d8bf0bf41cf8b3db7
Signed-off-by: Vincent Stehlé <[email protected]>
Cc: Romain Naour <[email protected]>
Signed-off-by: Thomas Petazzoni <[email protected]>