linker: esp32: fix empty iterable symbols
linker: esp32: fix empty iterable symbols

Z_ITERABLE_SECTION_ROM symbols were empty, meaning
that those symbols were not taking place in the linker script.

Signed-off-by: Sylvio Alves <bd63183a3ab542e2b25ff1e90971d4881e1bdbe5@espressif.com>

finikorg/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr