Partially revert an upstream commit to avoid build breakage
on Ubuntu.

Refrerence to discussion starting at
https://github.com/openwrt/packages/pull/16726#issuecomment-927309052

Upstream commit:
  ae9ac2a1bf
  meson: fix cross-compilation issues with gperf header file preprocessing

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>

Remove upstreamed patches.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

Faster compilation.

Backport upstream patch fixing cross compilation.

Signed-off-by: Rosen Penev <rosenp@gmail.com>