drivers: led: ht16k33: reprocess keyscan events in case of i2c error

Reprocess keyscan event processing in case of an I2C bus read
error. Otherwise, the HT16K33 will be stuck (when used in IRQ mode, not
in polling mode) and no new IRQs will be delivered.

Signed-off-by: Henrik Brix Andersen <henrik@brixandersen.dk>