board: dragonboard410c: Drop reflash functionality

board: dragonboard410c: Drop reflash functionality

This is broken ever since we switched to using U-Boot as first stage
bootloader. Since no one seems to test this actively, let's just drop this
entirely. There are other tools available for re-flashing the DB410c.

Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by:
Link: https://lore.kernel.org/r/20250407-db410c-fixes-v1-5-524aefbc8bb4@linaro.org
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>