bootloader: provide implementation of `abort`
bootloader: provide implementation of `abort`

ROM definition of `abort` was removed in 9240bbb. The old definition
resulted in a panic due to a jump to a null pointer (abort member in
ROM stub table was zero). The new definition triggers a debug
exception if JTAG is connected, or goes into an infinite loop to be
reset by the WDT.

armada-ai/esp-idf,espressif/esp-idf,www220/esp-idf,espressif/esp-idf,espressif/esp-idf,www220/esp-idf,www220/esp-idf,armada-ai/esp-idf,www220/esp-idf,www220/esp-idf,armada-ai/esp-idf,espressif/esp-idf,armada-ai/esp-idf