arm: dts: bcm283x: Allow UARTs to work before relocation

At present the pinctrl nodes are not enabled in pre-relocation U-Boot so
the UARTs do not correctly select the pinconfig to enable the UART pins.
Fix this so that the U-Boot banner is printed.

This fixes serial output on rpi_3b_32b with the following config.txt
options:

   enable_uart=1
   gpu_freq=250

Signed-off-by: Simon Glass <sjg@chromium.org>
Fixes: 9821636b64 (bcm2835_pinctrl: Probe pre-reloc)
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
diff --git a/arch/arm/dts/bcm283x-u-boot.dtsi b/arch/arm/dts/bcm283x-u-boot.dtsi
index 36548da..68d0362 100644
--- a/arch/arm/dts/bcm283x-u-boot.dtsi
+++ b/arch/arm/dts/bcm283x-u-boot.dtsi
@@ -19,3 +19,11 @@
 &gpio {
 	u-boot,dm-pre-reloc;
 };
+
+&uart0_gpio14 {
+	u-boot,dm-pre-reloc;
+};
+
+&uart1_gpio14 {
+	u-boot,dm-pre-reloc;
+};