The TSL2591 driver fails to initialize because the sensor responds with a
NACK on the initial RESET. Although the datasheet from Adafruit claims that
this is operation should be valid (RESET is part of the CONTROL register),
other sample non-Zephyr drivers provided by Arduino don't explicitly reset
the sensor on initialization (see
https://github.com/adafruit/Adafruit_TSL2591_Library/blob/master/Adafruit_TSL2591.cpp).
Thus, the assumption is that when the sensor is reset via software, it
doesn't respond to an ACK.
After removing the check for this initial RESET, the driver initializes
successfully.
Signed-off-by: Mohammed Billoo <mab@mab-labs.com>