build:kata: Remove autogen plic.h target
build:kata: Remove autogen plic.h target

smc_plic doesn't depend on opentitan/plic.h anymore

Change-Id: I095cfff70bbd0dca768248ad89132ac114c00f85
GitOrigin-RevId: 238fdd14e3671efbfed3beb33712d4eb86bf81ea

AmbiML/sparrow-build