Add modules/rockchip

Build rockchip modules as part of buildkernel.
Add the i2c controller module.

sys/modules/Makefile

@@ -331,6 +331,7 @@ SUBDIR=	\
 	${_rdrand_rng} \
 	re \
 	rl \
+	${_rockchip} \
 	rtwn \
 	rtwn_pci \
 	rtwn_usb \
@@ -563,6 +564,7 @@ _allwinner=	allwinner
 _armv8crypto=	armv8crypto
 _efirt=		efirt
 _em=		em
+_rockchip=	rockchip
 .endif
 
 .if ${MACHINE_CPUARCH} == "i386" || ${MACHINE_CPUARCH} == "amd64"

sys/modules/rockchip/Makefile

@@ -0,0 +1,7 @@
+# $FreeBSD$
+# Build modules specific to RockChip.
+
+SUBDIR = \
+	rk_i2c \
+
+.include <bsd.subdir.mk>

sys/modules/rockchip/rk_i2c/Makefile

@@ -0,0 +1,16 @@
+# $FreeBSD$
+
+.PATH: ${SRCTOP}/sys/arm64/rockchip
+
+KMOD=	rk_i2c
+SRCS=	rk_i2c.c
+
+SRCS+=	\
+	bus_if.h \
+	clknode_if.h \
+	device_if.h \
+	iicbus_if.h \
+	ofw_bus_if.h \
+	opt_platform.h \
+
+.include <bsd.kmod.mk>