removing clutter: INIT_blob provision The lost init.c source was reconstructed from init.obj in 2017; prior to that reconstruction we were compiling main.lib from partial source: using the init module in blob form with various binary patches, but recompiling create_RVtasks.c from source so we could change RiViera SWE configuration. We've been using the fully reconstructed version of init.c since 2017, and now the old INIT_blob provision (which is not used by any config) is just extra noise in our targets/*.conf files. This commit removes all bits related to this provision, reducing clutter and making it easier to add new targets.

flash-script:	fwimage.bin
	../helpers/mk-flash-script $< ${FLASH_BASE_ADDR} ${FLASH_SECTOR_SIZE} \
		> $@