Revert "ANDROID: tty: serdev: Fix broken serial console input"

We don't need this any more as devices which are consoles and also
platform devices are automatically excluded from binding unless the user
opts into it.

This reverts commit 2fdad105.

Bug: 146517987
Change-Id: I2b9cc9c13870e5ecccbf04addadd48e59658aee3
Signed-off-by: Alistair Delva <adelva@google.com>