Revert all kernel & recovery customizations

Revert "[HAX] Allow per-target dtbTool"

This reverts commit a0b3b0d1424243f7822500683a11beea8da5a438.

Revert "build: use the system's ccache by default"

This reverts commit 557572b70889bd8cac8e65d0429a725a106e42ae.

Revert "kernel: Ignore errors with module building"

This reverts commit 2a599cb39014a32634e12d49c3594b5f03ffc7e6.

Revert "Make the kernel image format parametric instead of a chain of if/elses"

This reverts commit 2fcb3da87f70b6fc8349519dad5910e357e70e70.

Revert "add recovery and kernel changes"

This reverts commit 4b1e7f26385fa04aa7bb18d9a9db9e1bc62afe1d.

Change-Id: I4d441b358672a1e522d679d723b147815949adab