u-boot-rock64: remove unreferenced file

sysutils/u-boot-rock64/u-boot-rockchip.mk

@@ -1,42 +0,0 @@
-#	$NetBSD: u-boot-rockchip.mk,v 1.3 2021/06/25 08:28:57 mrg Exp $
-#
-# used by sysutils/u-boot-rock64/Makefile
-
-# Common makefile fragment for rockchip based u-boot targets.
-#
-# Set these variables:
-#
-#	UBOOT_IMAGE_TYPE	("rk3399", "rk3328")
-#
-
-UBOOT_VERSION=	${GITHUB_TAG:C/-.*$//}
-MASTER_SITES=	${MASTER_SITE_GITHUB:=ayufan-rock64/}
-GITHUB_PROJECT=	linux-u-boot
-GITHUB_TAG=	2017.09-rockchip-ayufan-1063-g29843fbd42
-DISTNAME=	${GITHUB_TAG}
-PATCHDIR=	${.CURDIR}/../../sysutils/u-boot-rock64/patches
-DISTFILES=	${DEFAULT_DISTFILES}
-EXTRACT_SUFX=	.tar.gz
-
-# pkgsrc tries to run distfiles that end in .bin; handle manually
-EXTRACT_ONLY=	${DISTFILES:N*.bin}
-
-USE_TOOLS+=	gawk
-MAKE_ENV+=	BL31=${WRKDIR}/${BL31}
-
-post-extract:
-	cp ${DISTDIR}/${DDR_BIN} ${WRKDIR}
-
-post-build:
-# build stage 3 package
-	cd ${WRKSRC} && ${SETENV} ${MAKE_ENV} ${MAKE_PROGRAM} u-boot.itb
-# build stage 1 loader
-	${WRKSRC}/tools/mkimage -n ${UBOOT_IMAGE_TYPE} -T rksd -d ${WRKDIR}/${DDR_BIN} ${WRKSRC}/idbloader.img
-# append stage2 loader
-	cat ${WRKSRC}/spl/u-boot-spl.bin >> ${WRKSRC}/idbloader.img
-# wrap everything up into a single file that can be written to an SD card
-	cp ${WRKSRC}/idbloader.img ${WRKSRC}/rksd_loader.img
-	dd if=${WRKSRC}/u-boot.itb seek=448 conv=notrunc of=${WRKSRC}/rksd_loader.img
-# build SPI NOR flash image. See dev-ayufan/build.mk.
-	set -e; b=0; while [ "$$b" != 128 ]; do dd bs=2k count=1; dd if=/dev/zero bs=2k count=1; b=$$(expr $$b + 1); done < ${WRKSRC}/idbloader.img > ${WRKSRC}/rkspi_loader.img 2> /dev/null
-	dd if=${WRKSRC}/u-boot.itb seek=1024 conv=notrunc of=${WRKSRC}/rkspi_loader.img