arm64: dts: ti: k3-am642-phyboard-electra-x27-gpio1-spi1-uart3: Fix schema warnings

Rename pinctrl nodes to comply with naming conventions required by
pinctrl-single schema. Also, replace invalid integer assignment in
SPI node with a boolean to align with omap-spi schema.

Fixes: 638ab30ce4c6 ("arm64: dts: ti: am64-phyboard-electra: Add DT overlay for X27 connector")
Signed-off-by: Wadim Egorov <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Nishanth Menon <[e-mail]>

arch/arm64/boot/dts/ti/k3-am642-phyboard-electra-x27-gpio1-spi1-uart3.dtso

···
 };
 
 &main_pmx0 {
-	main_gpio1_exp_header_gpio_pins_default: main-gpio1-exp-header-gpio-pins-default {
+	main_gpio1_exp_header_gpio_pins_default: main-gpio1-exp-header-gpio-default-pins {
 		pinctrl-single,pins = <
 			AM64X_IOPAD(0x0220, PIN_INPUT, 7)	/* (D14) SPI1_CS1.GPIO1_48 */
 		>;
 	};
 
-	main_spi1_pins_default: main-spi1-pins-default {
+	main_spi1_pins_default: main-spi1-default-pins {
 		pinctrl-single,pins = <
 			AM64X_IOPAD(0x0224, PIN_INPUT, 0)	/* (C14) SPI1_CLK */
 			AM64X_IOPAD(0x021C, PIN_OUTPUT, 0)	/* (B14) SPI1_CS0 */
···
 		>;
 	};
 
-	main_uart3_pins_default: main-uart3-pins-default {
+	main_uart3_pins_default: main-uart3-default-pins {
 		pinctrl-single,pins = <
 			AM64X_IOPAD(0x0048, PIN_INPUT, 2)       /* (U20) GPMC0_AD3.UART3_RXD */
 			AM64X_IOPAD(0x004c, PIN_OUTPUT, 2)      /* (U18) GPMC0_AD4.UART3_TXD */
···
 &main_spi1 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&main_spi1_pins_default>;
-	ti,pindir-d0-out-d1-in = <1>;
+	ti,pindir-d0-out-d1-in;
 	status = "okay";
 };