Backport dkms fix for some linux-kernel builds

[Gustavo Almeida]

Hi,

I'm trying to build kernel module for Ubuntu noble, using linux-headers 6.8.0-124, against the tag mr14.1.1.x (x --> .13), and i'm facing some problems.

I'm facing the exact same fail described here: https://github.com/sipwise/rtpengine/pull/2085 .

As 14.1.1.x share the same function templates used in mr26.0.x, i think this should also be backported to 14.1.1.x.

I already test with mr26.0.x and it indeeds solves the problem.

Log:

```sh

  The kernel was built by: x86_64-linux-gnu-gcc-13 (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0
  You are using:           gcc-13 (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0
  CC [M]  /var/lib/dkms/ngcp-rtpengine/14.1.1.13+0~mr14.1.1.13/build/nft_rtpengine.o
/var/lib/dkms/ngcp-rtpengine/14.1.1.13+0~mr14.1.1.13/build/nft_rtpengine.c:6892:35: error: initialization of 'int (*)(const struct nft_ctx *, const struct nft_expr *)' from incompatible pointer type 'int (*)(const struct nft_ctx *, const struct nft_expr *, const struct nft_data **)' [-Werror=incompatible-pointer-types]
 6892 |         .validate               = rtpengine_expr_validate,
      |                                   ^~~~~~~~~~~~~~~~~~~~~~~
/var/lib/dkms/ngcp-rtpengine/14.1.1.13+0~mr14.1.1.13/build/nft_rtpengine.c:6892:35: note: (near initialization for 'rtpengine_inet_ops.validate')
/var/lib/dkms/ngcp-rtpengine/14.1.1.13+0~mr14.1.1.13/build/nft_rtpengine.c:6904:35: error: initialization of 'int (*)(const struct nft_ctx *, const struct nft_expr *)' from incompatible pointer type 'int (*)(const struct nft_ctx *, const struct nft_expr *, const struct nft_data **)' [-Werror=incompatible-pointer-types]
 6904 |         .validate               = rtpengine_expr_validate,
      |                                   ^~~~~~~~~~~~~~~~~~~~~~~
/var/lib/dkms/ngcp-rtpengine/14.1.1.13+0~mr14.1.1.13/build/nft_rtpengine.c:6904:35: note: (near initialization for 'rtpengine_ipv4_ops.validate')
/var/lib/dkms/ngcp-rtpengine/14.1.1.13+0~mr14.1.1.13/build/nft_rtpengine.c:6916:35: error: initialization of 'int (*)(const struct nft_ctx *, const struct nft_expr *)' from incompatible pointer type 'int (*)(const struct nft_ctx *, const struct nft_expr *, const struct nft_data **)' [-Werror=incompatible-pointer-types]
 6916 |         .validate               = rtpengine_expr_validate,
      |                                   ^~~~~~~~~~~~~~~~~~~~~~~
/var/lib/dkms/ngcp-rtpengine/14.1.1.13+0~mr14.1.1.13/build/nft_rtpengine.c:6916:35: note: (near initialization for 'rtpengine_ipv6_ops.validate')
cc1: some warnings being treated as errors
make[2]: *** [scripts/Makefile.build:243: /var/lib/dkms/ngcp-rtpengine/14.1.1.13+0~mr14.1.1.13/build/nft_rtpengine.o] Error 1
make[1]: *** [/usr/src/linux-headers-6.8.0-124-generic/Makefile:1936: /var/lib/dkms/ngcp-rtpengine/14.1.1.13+0~mr14.1.1.13/build] Error 2
make: *** [Makefile:240: __sub-make] Error 2
make: Leaving directory '/usr/src/linux-headers-6.8.0-124-generic'

``` 

Thank you,

Gustavo Almeida