Revert "ANDROID: keychord: Fix a slab out-of-bounds read."

This reverts commit 913d980e.

Remove keychord driver, replaced in user space by
https://android-review.googlesource.com/c/677629

.

Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Cc: Amit Pundir <amit.pundir@linaro.org>
Bug: 64114943
Bug: 63962952
Bug: 129556081
Change-Id: I0a652b72b0ee62974c408ffb0987cc2ef9e346c1