libre: Add arm-linux-gnueabi-linux-api-headers 4.19
    
    This PKGBUILD is based on the
    aarch64-linux-gnu-linux-libre-api-headers PKGBUILD.
    
    It is needed for packaging arm-linux-gnueabi-glibc.
    
    Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>