src: Drop unused '#include <halt.h>'

Change-Id: Ie7afe77053a21bcf6a1bf314570f897d1791a620
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31921
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/soc/intel/skylake/pmutil.c

@@ -27,7 +27,6 @@
 #include <device/pci_def.h>
 #include <console/console.h>
 #include <intelblocks/pmclib.h>
-#include <halt.h>
 #include <intelblocks/lpc_lib.h>
 #include <intelblocks/tco.h>
 #include <stdlib.h>