Update fw_update comments.
#
# NOTE: Older fimware versions are no longer supported by the host driver.
# NOTE: The latest firmware (19.6.1) only works on ATWINC1500-MR210PB.
+# NOTE: Firmware is at <openmv-ide-install-dir>/share/qtcreator/firmware/WINC1500/winc_19_6_1.bin
import network
