Set hint.acpi.0.disable to 1 in /boot/loader.rc of {boot,kern}.flp,

since we have no ACPI feature in the installation kernel at this time.

Without having this, we'll see

	ACPI no autoload failed -- no such file or directory

message at boot time, and it makes some confusion to the users.  We can
backout this change if installation kernel has ACPI feature.

PR:		36911 (partly)

release/Makefile

@@ -1009,6 +1009,7 @@ doMFSKERN:
 	@echo "read" >> ${RD}/image.${FSIMAGE}/boot/loader.rc
 .endif
 	@echo "load -t mfs_root /mfsroot" >> ${RD}/image.${FSIMAGE}/boot/loader.rc
+	@echo "set hint.acpi.0.disable=1" >> ${RD}/image.${FSIMAGE}/boot/loader.rc
 	@echo "echo \\007\\007" >> ${RD}/image.${FSIMAGE}/boot/loader.rc
 	@echo "autoboot 10" >> ${RD}/image.${FSIMAGE}/boot/loader.rc
 .if ${MACHINE_ARCH} == "i386" && ${AUTO_KEYBOARD_DETECT}