Thanks to David's patches, we can now simplify these makefiles

further, and just use PROG directly (without FILES).

Suggested by:	bde

sys/boot/i386/boot0/Makefile

@@ -1,12 +1,10 @@
 # $FreeBSD$
 
-PROG=	${BOOT}
-INTERNALPROG=
-FILES=	${BOOT}
+PROG?=	boot0
+STRIP=
+BINMODE=${NOBINMODE}
 NOMAN=
-SRCS=	${BOOT}.S
-
-BOOT?=	boot0
+SRCS=	${PROG}.S
 
 # The default set of flags compiled into boot0.  This enables update (writing
 # the modified boot0 back to disk after running so that the selection made is

sys/boot/i386/boot0ext/Makefile

@@ -2,6 +2,6 @@
 
 .PATH: ${.CURDIR}/../boot0
 
-BOOT=	boot0ext
+PROG=	boot0ext
 
 .include "${.CURDIR}/../boot0/Makefile"

sys/boot/i386/boot0sio/Makefile

@@ -2,7 +2,7 @@
 
 .PATH: ${.CURDIR}/../boot0
 
-FILESNAME=	boot0sio
+PROGNAME=	boot0sio
 CFLAGS+=	-DSIO
 
 .include "${.CURDIR}/../boot0/Makefile"

sys/boot/i386/cdboot/Makefile

@@ -1,12 +1,11 @@
 # $FreeBSD$
 
-PROG=	${BOOT}
-INTERNALPROG=
-FILES=	${BOOT}
+PROG=	cdboot
+STRIP=
+BINMODE=${NOBINMODE}
 NOMAN=
-SRCS=	${BOOT}.s
+SRCS=	${PROG}.s
 
-BOOT=	cdboot
 ORG=	0x7c00
 
 LDFLAGS=-N -e start -Ttext ${ORG} -Wl,-S,--oformat,binary

sys/boot/i386/mbr/Makefile

@@ -1,12 +1,11 @@
 # $FreeBSD$
 
-PROG=	${BOOT}
-INTERNALPROG=
-FILES=	${BOOT}
+PROG=	mbr
+STRIP=
+BINMODE=${NOBINMODE}
 NOMAN=
-SRCS=	${BOOT}.s
+SRCS=	${PROG}.s
 
-BOOT=	mbr
 ORG=	0x600
 
 LDFLAGS=-N -e start -Ttext ${ORG} -Wl,-S,--oformat,binary