changed so the linkerscript is passed through the preprocessor #422

Job	Run time
Build each header individually	1m 1s
build (lpc802)	18s
build (stm32f407)	12s
build (atsam3x8e)	13s
build (lpc1788)	18s
build (lpc1759)	20s
build (lpc1752)	20s
build (stm32f103)	14s
build (atsam4s2b)	19s
build (rp2350)	13s
build (max32625)	18s
build (stm32h723)	20s
build (tmpm373)	16s
build (mb9bf566k)	20s
build (lpc1756)	21s
build (max32660)	14s
build (lpc1754)	15s
build (lpc55s66)	19s
	5m 51s

Provide feedback