Remove: sys/dts/arm/overlays/spigen-rpi-b.dtso

Remove SPIGEN device tree overlay used with rpi-b (BCM2835/armv6)

Approved by: manu (mentor)
Differential revision: https://reviews.freebsd.org/D54188

sys/dts/arm/overlays/spigen-rpi-b.dtso

@@ -1,30 +0,0 @@
-
-/dts-v1/;
-/plugin/;
-
-/ {
-	compatible = "brcm,bcm2835";
-};
-
-&{/soc/spi@7e204000} {
-	status = "okay";
-
-	spigen0: spigen0 {
-		compatible = "freebsd,spigen";
-		reg = <0>;
-		spi-max-frequency = <500000>; /* Req'd property, override with spi(8) */
-		status = "okay";
-	};
-	spigen1: spigen1 {
-		compatible = "freebsd,spigen";
-		reg = <1>;
-		spi-max-frequency = <500000>; /* Req'd property, override with spi(8) */
-		status = "okay";
-	};
-};
-
-&{/soc/gpio@7e200000/spi0_cs_pins} {
-	brcm,pins = <8 7>;
-	brcm,function = <4>; /* ALT0 */
-};
-

sys/modules/dtb/rpi/Makefile

@@ -1,7 +1,6 @@
 # DTS files for the 32-bit and 64-bit arm-based Raspberry Pi family of devices
 .if ${MACHINE_CPUARCH} == "arm"
 DTSO=	\
-	spigen-rpi-b.dtso \
 	spigen-rpi2.dtso
 .elif ${MACHINE_CPUARCH} == "aarch64"
 DTSO=	\