The leading - makes it rather inconsistent with the majority of other
projects around the world. Use the form everyone else uses.
To solve this, properly pass prefix to inner makes as was always
intended.
Fixes: https://github.com/libopencm3/libopencm3/issues/1058
here, it's a bit of a mess.. G0 flash controller does not really
match exsting feature split. IE it has instruction cache only ..
so, no flash_idcache.c as it. flash_common_f could be used, but
flash_unlock would not take care of option byte ?
prefetch, icache and lock is ok. I had no look at flash programming
or erase yet..
