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.

LINK_SCRIPT_SRC=src/cs/system/template/gsm_ds_motc139.template
MAIN_blob=blobs/patches/main-rvtmodem.lib
TPUDRV_blob=
FLASH_BASE_ADDR=0x10000
FLASH_SECTOR_SIZE=0x10000
RVTMUX_ON_MODEM=1