The Debian LTS kernel does not have CONFIG_ACPI_I2C_OPREGION set. This
is likely due to its dependency on CONFIG_I2C=y. Thus explicitly set
those two options.
This commit reverts upstream commit
9945722afdc3443eab826b2da1122509a13a50a5 (builddeb: make headers package thinner)
which drops some files from the linux-headers package. These files seem
to be required by some out-of-tree modules (see #170).
