[nrf fromlist] dfu: Add missing depends on for progressive erase

Adds a depends on that requires the underlying driver support
explicit erase

Upstream PR: zephyrproject-rtos/zephyr#79090

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>

subsys/dfu/Kconfig

@@ -69,6 +69,7 @@ config IMG_BLOCK_BUF_SIZE
 config IMG_ERASE_PROGRESSIVELY
  bool "Erase flash progressively when receiving new firmware"
  select STREAM_FLASH_ERASE
+ depends on FLASH_HAS_EXPLICIT_ERASE
  help
  If enabled, flash is erased as necessary when receiving new firmware,
  instead of erasing the whole image slot at once. This is necessary