implemented ability to enable -D_FF_RV_EXIST_ in TIF library It is not clear if this quirk is intentional or not, but TI's production version of tif_na7_db_{fl,ir}.lib was built without -D_FF_RV_EXIST_, and as a result, the code that is present in the source for the TRACEMASK_IN_FFS feature was not compiled in, making the feature unavailable. The present change makes it possible to re-enable this code (when TIF libraries are being rebuilt from source rather than used as blobs) by setting TRACEMASK_IN_FFS=1 on the configure line. The new code is NOT enabled by default: it is not a change which we can justify inflicting on our production firmwares.

########################################
# LIBRARIES / MODULES definition       #
########################################

# to avoid multiple nucleus.def (import + include) 
ifndef NUCLEUS_DEF
   NUCLEUS_DEF = 1

### Nucleus libraries
###########################

  ifeq ($(OP_L1_STANDALONE),1)
    OUT_OS_LIB_DIR = $(OUT_LIB_DIR)
  endif

  export OS_FLASH_LIB     = $(OUT_OS_LIB_DIR)/nucleus_flash.lib
  export OS_INT_RAM_LIB   = $(OUT_OS_LIB_DIR)/nucleus_int_ram.lib
  export OS_LIB          := $(OS_FLASH_LIB) $(OS_INT_RAM_LIB)

  MODULES     += $(OS_NUC_DIR)

endif