ANDROID: keychord: Check for write data size

keychord driver causes a kernel warning when writing more than
(1 << (MAX_ORDER - 1)) * PAGE_SIZE bytes to /dev/keychord.
In reality writes to this file should be much smaller, so
limiting data size to PAGE_SIZE seems to be appropriate.
This change checks write data size and if it's more than
PAGE_SIZE causes write to fail.

Bug: 73962978

Change-Id: I8a064a396d4259ffca924fa35d80e9700c4f8d79
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: ahmedradaideh <ahmed.radaideh@gmail.com>