apalis-imx8: remove -u-boot.dtsi include

This file is included automatically since quite some time now.

From documentation:

U-Boot automatically looks for and includes a file with updates
to the standard devicetree for your board, searching for them in
the same directory as the main file, in this order:

<orig_filename>-u-boot.dtsi
<CONFIG_SYS_SOC>-u-boot.dtsi
<CONFIG_SYS_CPU>-u-boot.dtsi
<CONFIG_SYS_VENDOR>-u-boot.dtsi
u-boot.dtsi

Signed-off-by: Andrejs Cainikovs <andrejs.cainikovs@toradex.com>

arch/arm/dts/fsl-imx8qm-apalis.dts

@@ -9,7 +9,6 @@
 /memreserve/ 0x80000000 0x00020000;
 
 #include "fsl-imx8qm.dtsi"
-#include "fsl-imx8qm-apalis-u-boot.dtsi"
 
 / {
 	model = "Toradex Apalis iMX8";