Change in coreboot[master]: soc/apollolake: Create components required for IFWI stitching

[Arthur Heymans (Code Review)]

Attention is currently required from: Sean Rhodes, Nico Huber, Martin Roth, Andrey Petrov, Patrick Rudolph.
Arthur Heymans has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/61872 )

Change subject: soc/apollolake: Create components required for IFWI stitching
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Patch Set 14:

(1 comment)

File Makefile.inc:

https://review.coreboot.org/c/coreboot/+/61872/comment/47112120_c217eba7 
PS14, Line 1321: $(objcbfs)/ibbm.rom:
               : 	# Size is calculate as:
               : 	# IBBP-Sub-Partition - IBBL - Manifest - BPM.met - Padding
               : 	python -c "import struct; fp = open ('$@', 'wb'); \
               : 		fp.write (b'\xFF' * \
               : 		$(shell echo $$((32768 - \
               : 		$(shell stat -Lc %s $(objcbfs)/ibbl.rom) \
               : 		- 748 - 180 - 3168)))); fp.close();"
               : 	printf "\nBuilt $@ (0x%x)\n" `stat -c "%s" $@`
Does this need a dependency? Also inline python inside makefiles is a bad idea.
"dd if=/dev/zero bs=1 count=#filesize | tr "\000" "\377" > foo" could achieve the same?