Fix: Missed CS1 Pin for SPI1

Signed-off-by: Patrick Menschel <menschel.p@posteo.de>

src/arm/am335x-boneblue.dts

@@ -275,12 +275,14 @@
 		>;
 	};
 
+	/* Spi 1 on external connectors JST-SH 6-pin connectors S1.0 and S1.1 */
 	spi1_pins: pinmux_spi1_pins {
 		pinctrl-single,pins = <
 			AM33XX_PADCONF(AM335X_PIN_MCASP0_ACLKX, PIN_INPUT, MUX_MODE3)		/* (A13) mcasp0_aclkx.spi1_sclk */
 			AM33XX_PADCONF(AM335X_PIN_MCASP0_FSX, PIN_INPUT, MUX_MODE3)		/* (B13) mcasp0_fsx.spi1_d0 */
 			AM33XX_PADCONF(AM335X_PIN_MCASP0_AXR0, PIN_INPUT, MUX_MODE3)		/* (D12) mcasp0_axr0.spi1_d1 */
 			AM33XX_PADCONF(AM335X_PIN_MCASP0_AHCLKR, PIN_INPUT, MUX_MODE3)		/* (C12) mcasp0_ahclkr.spi1_cs0 */
+			AM33XX_PADCONF(AM335X_PIN_ECAP0_IN_PWM0_OUT, PIN_INPUT, MUX_MODE2)	/* (C18) ecap0_in_pwm0_out.spi1_cs1 */
 		>;
 	};
 };