arm: dts: socfpga: remove spurious execute permission from dt files

It doesn't make sense for these files to have the x bit set. It was,
probably accidentally, added in:

Fixes: 2c494e62c31a (arm: dts: Stratix10: Add QSPI node)
Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>
diff --git a/arch/arm/dts/socfpga_stratix10.dtsi b/arch/arm/dts/socfpga_stratix10.dtsi
old mode 100755
new mode 100644
diff --git a/arch/arm/dts/socfpga_stratix10_socdk-u-boot.dtsi b/arch/arm/dts/socfpga_stratix10_socdk-u-boot.dtsi
old mode 100755
new mode 100644
diff --git a/arch/arm/dts/socfpga_stratix10_socdk.dts b/arch/arm/dts/socfpga_stratix10_socdk.dts
old mode 100755
new mode 100644