ARM: dts: exynos: drop unsupported desc-num in Exynos3250

There is no desc-num property for MMC nodes:

  exynos3250-monk.dtb: mmc@12510000: Unevaluated properties are not allowed ('desc-num' was unexpected)

Link: https://lore.kernel.org/r/20230120155404.323386-3-krzysztof.kozlowski@linaro.orgSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

arch/arm/boot/dts/exynos3250-monk.dts

@@ -438,7 +438,6 @@ &mshc_0 {
 	broken-cd;
 	non-removable;
 	cap-mmc-highspeed;
-	desc-num = <4>;
 	mmc-hs200-1_8v;
 	card-detect-delay = <200>;
 	vmmc-supply = <&vemmc_reg>;

arch/arm/boot/dts/exynos3250-rinato.dts

@@ -619,7 +619,6 @@ &mshc_0 {
 	broken-cd;
 	non-removable;
 	cap-mmc-highspeed;
-	desc-num = <4>;
 	mmc-hs200-1_8v;
 	card-detect-delay = <200>;
 	vmmc-supply = <&ldo12_reg>;