kboot: List sources one per line to make merges easier

Make SRC an alphabetical list of files, one per line.

Sponsored by:		Netflix

stand/kboot/Makefile

@@ -18,9 +18,18 @@ NEWVERSWHAT=	"kboot loader" ${MACHINE_ARCH}
 INSTALLFLAGS=	-b
 
 # Architecture-specific loader code
-SRCS=		crt1.c conf.c vers.c main.c host_syscalls.c hostcons.c hostdisk.c kbootfdt.c gfx_fb_stub.c
-SRCS+=		init.c
-SRCS+=		termios.c
+SRCS=	\
+		conf.c \
+		crt1.c \
+		gfx_fb_stub.c \
+		host_syscalls.c \
+		hostcons.c \
+		hostdisk.c \
+		init.c \
+		kbootfdt.c \
+		main.c \
+		termios.c \
+		vers.c \
 
 CFLAGS.gfx_fb_stub.c += -I${SRCTOP}/contrib/pnglite -I${SRCTOP}/sys/teken