schroot: add missing realpath, stat & tac deps; update openwrt patch

[jmarcet]

Maintainer: me Compile tested: master x86_64 Run tested: master x86_64

Description: As reported in this issue, there are two missing deps in the package, as is.

I have updated the patch to change all stat calls to be compatible with busybox and add the new deps. The path is dropped to make all stat calls the same, there is at least one more which already uses the new format.

I was not sure how to add the busybox's stat option, since it also needs an additional feature enabled.

[alex9434]

Hi @jmarcet, want to confirm that I successfully compiled this commit. Will test next week and report back if I run into any issues. Thank you so much for the quick support!