Drop drivers/generic/debug

Not very popular nor useful nowadays.

Change-Id: I3dc0f7aaf188950a43f5350d3a95669fbbdcfd94
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/4554
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
37 files changed