gdal is broken because optional dependency hdf4 is broken

[Thra11]

Describe the bug
hdf4 no longer builds in nixpkgs unstable. It looks like something's changed in the compiler or glibc meaning that non-standard types such as uint32 are no longer available in the global namespace. It is in 'maintenance mode' / deprecated upstream. Not sure if this will be fixable or whether we should consider dropping hdf4 / making hdf4 optional for packages such as gdal where it is an optional dependency upstream but a required dependency in nixpkgs.

To Reproduce
Steps to reproduce the behavior:

1. nix-build '<nixpkgs>' -A gdal

Notify maintainers
@knedlsepp @MarcWeber

Metadata
Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

 - system: `"aarch64-linux"`
 - host os: `Linux 5.10.0-rc5, NixOS, 21.03.git.4648938bb44M (Okapi)`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.3.10`
 - channels(root): `"nixos-20.03.git.0c1c18c"`
 - nixpkgs: `/home/thrall/nixpkgs`

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute: hdf4 gdal mapnik
# a list of nixos modules affected by the problem
module:

[knedlsepp]

Thx for the notification! It seems this problem is specific to aarch64. It still builds fine on
x86_64. I'll try to have a look. If we cannot make hdf4 build on ARM again, we can disable hdf4 support for gdal on aarch64.