refactor to remove SPI; no need for shared DTSI

app/boards/shields/romac/boards/nice_nano.overlay

@@ -1,10 +0,0 @@
-&spi1 {
-	compatible = "nordic,nrf-spi";
-	/* Cannot be used together with i2c0. */
-	status = "okay";
-	sck-pin = <5>;
-	mosi-pin = <6>;
-	miso-pin = <7>;
-
-};
-

app/boards/shields/romac/romac.conf

@@ -1,2 +0,0 @@
-CONFIG_ZMK_RGB_UNDERGLOW=n
-CONFIG_WS2812_STRIP=n

app/boards/shields/romac/romac.dtsi

@@ -1,50 +0,0 @@
-/*
- * Copyright (c) 2020 Pete Johansen, Richard Jones
- *
- * SPDX-License-Identifier: MIT
- */
-
-#include <dt-bindings/zmk/matrix-transform.h>
-
-/ {
-	chosen {
-		zmk,kscan = &kscan0;
-		zmk,matrix_transform = &default_transform;
-	};
-
-	default_transform: keymap_transform_0 {
-		compatible = "zmk,matrix-transform";
-		columns = <3>;
-		rows = <4>;
-// | SW1  | SW2  | SW3  |
-// | SW4  | SW5  | SW6  |
-// | SW7  | SW8  | SW9  |
-// | SW10 | SW11 | SW12 |
-		map = <
-RC(0,0) RC(0,1) RC(0,2)
-RC(1,0) RC(1,1) RC(1,2)
-RC(2,0) RC(2,1) RC(2,2)
-RC(3,0) RC(3,1) RC(3,2)
-		>;
-	};
-
-	kscan0: kscan {
-		compatible = "zmk,kscan-gpio-matrix";
-		label = "KSCAN";
-
-		diode-direction = "col2row";
-		row-gpios
-			= <&pro_micro_d 4 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)>
-			, <&pro_micro_d 5 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)>
-			, <&pro_micro_d 6 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)>
-			, <&pro_micro_d 7 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)>
-			;
-
-	};
-
-	bt_unpair_combo: bt_unpair_combo {
-		compatible = "zmk,bt-unpair-combo";
-	};
-
-};
-

app/boards/shields/romac/romac.overlay

@@ -4,16 +4,54 @@
  * SPDX-License-Identifier: MIT
  */
 
-#include "romac.dtsi"
+#include <dt-bindings/zmk/matrix-transform.h>
+
+/ {
+	chosen {
+		zmk,kscan = &kscan0;
+		zmk,matrix_transform = &default_transform;
+	};
+
+	default_transform: keymap_transform_0 {
+		compatible = "zmk,matrix-transform";
+		columns = <3>;
+		rows = <4>;
+// | SW1  | SW2  | SW3  |
+// | SW4  | SW5  | SW6  |
+// | SW7  | SW8  | SW9  |
+// | SW10 | SW11 | SW12 |
+		map = <
+RC(0,0) RC(0,1) RC(0,2)
+RC(1,0) RC(1,1) RC(1,2)
+RC(2,0) RC(2,1) RC(2,2)
+RC(3,0) RC(3,1) RC(3,2)
+		>;
+	};
+
+	kscan0: kscan {
+		compatible = "zmk,kscan-gpio-matrix";
+		label = "KSCAN";
+
+		diode-direction = "col2row";
+		row-gpios
+			= <&pro_micro_d 4 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)>
+			, <&pro_micro_d 5 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)>
+			, <&pro_micro_d 6 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)>
+			, <&pro_micro_d 7 (GPIO_ACTIVE_HIGH | GPIO_PULL_DOWN)>
+			;
 
-&kscan0 {
 		col-gpios
 			= <&pro_micro_a  0 GPIO_ACTIVE_HIGH>
 			, <&pro_micro_d 15 GPIO_ACTIVE_HIGH>
 			, <&pro_micro_d 14 GPIO_ACTIVE_HIGH>
 			;
+
 	};
 
-&bt_unpair_combo {
+	bt_unpair_combo: bt_unpair_combo {
+		compatible = "zmk,bt-unpair-combo";
 		key-positions = <0 11>;
 	};
+
+};
+