generic: keep module aliases inside .modinfo

generic: keep module aliases inside .modinfo

It seems module aliases are actually essential info.  E.g. other modules
may call xt_request_find_match(NFPROTO_IPV{4,6}, "hashlimit", 1) and the
kernel will request user mode modprobe helper for ipt_hashlimit and
ip6t_hashlimit respectively which are aliases of xt_hashlimit.ko

Compile-tested for armvirt, there is nearly no size impact.

Before

    -rw-r--r-- 1 yousong yousong     304 Jan 10 17:37 config.seed
    -rw-r--r-- 1 yousong yousong    1634 Jan 11 11:07 lede-armvirt-default.manifest
    -rw-r--r-- 1 yousong yousong 1533647 Jan 11 11:07 lede-armvirt-default-rootfs.tar.gz
    -rw-r--r-- 1 yousong yousong 1802711 Jan 11 11:07 lede-armvirt-root.ext4.gz
    -rw-r--r-- 1 yousong yousong 1544597 Jan 11 11:07 lede-armvirt-rootfs.cpio.gz
    -rw-r--r-- 1 yousong yousong 1174984 Jan 11 11:07 lede-armvirt-root.squashfs.gz
    -rwxr-xr-x 1 yousong yousong 1654712 Jan 11 11:07 lede-armvirt-zImage
    -rwxr-xr-x 1 yousong yousong 2738296 Jan 11 11:07 lede-armvirt-zImage-initramfs
    drwxr-xr-x 2 yousong yousong    4096 Jan 10 17:35 packages
    -rw-r--r-- 1 yousong yousong     739 Jan 10 17:37 sha256sums

After

    -rw-r--r-- 1 yousong yousong     304 Jan 10 17:37 config.seed
    -rw-r--r-- 1 yousong yousong    1634 Jan 11 11:10 lede-armvirt-default.manifest
    -rw-r--r-- 1 yousong yousong 1533646 Jan 11 11:10 lede-armvirt-default-rootfs.tar.gz
    -rw-r--r-- 1 yousong yousong 1802711 Jan 11 11:10 lede-armvirt-root.ext4.gz
    -rw-r--r-- 1 yousong yousong 1544593 Jan 11 11:10 lede-armvirt-rootfs.cpio.gz
    -rw-r--r-- 1 yousong yousong 1174984 Jan 11 11:10 lede-armvirt-root.squashfs.gz
    -rwxr-xr-x 1 yousong yousong 1654736 Jan 11 11:10 lede-armvirt-zImage
    -rwxr-xr-x 1 yousong yousong 2738144 Jan 11 11:10 lede-armvirt-zImage-initramfs
    drwxr-xr-x 2 yousong yousong    4096 Jan 10 17:35 packages
    -rw-r--r-- 1 yousong yousong     739 Jan 10 17:37 sha256sums

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>