A board_config may define BOARD_HAS_MTD_PARTITION_OVERRIDE to
   uses it's own number of partitions and names.

   If a BOARD_HAS_MTD_PARTITION_OVERRIDE is not defined
   the hardcoded original values of fs/mtd_params &
   /fs/mtd_waypoints are used.

on an mtd device.

  Erases and write operations will use the BOARD_EEPROM_WP_CTRL
  macro to remove the Write protection and restore it.

  To simplify integration of an EEPROM device with a Write Protect
  control pin, we add an overidable BOARD_EEPROM_WP_CTRL macro
  the does nothing.

  A board that provids the GPIO for WP should define
  BOARD_EEPROM_WP_CTRL(_protected_true) that will set the WP GPIO
  to the Protected state when passed true.

  This is an intrim nuttx patch that fixes the missing CONFIG_
  prefix on RAMTRON_WRITEWAIT. PR submitted upstream. This will
  be in affect until the next uptake of upstream NuttX

UART4 and UART5 are not USART instances.

  This prevents the meta value of 0 => not used from being passed to
  px4_arch_configgpio. As this would map to PORTA|PIN0 and is not
  the intended configuration.

  This prevents the meta value of 0 => not used from being passed to
  px4_arch_configgpio. As this would map to PORTA|PIN0 and is not
  the intended use.

This removes the necessity, that the driver class ID matches the uorb topic
instance.

Also improve error handling & reporting

needed for the next commit

- reduces some code duplication
- provides clear API & separation for temp compensation

additional changes:
- added timestamp to sensor_correction topic
- reduced its publication rate, to only when voting index or scales or
  offsets change (if there is more than 1deg change in temperature)