The Simple Boot feature for Espressif chips is a method of booting
that doesn't depend on a 2nd stage bootloader. Its not the
intention to replace a 2nd stage bootloader such as MCUboot and
ESP-IDF bootloader, but to have a minimal and straight-forward way
of booting, and also simplify the building.
This commit also makes this bootloader configuration as default
for esp32c3-generic target and removes the need for running
'make bootloader' command for it.
Signed-off-by: Almir Okato <almir.okato@espressif.com>