arm64: dts: exynos: Remove num-slots from exynos platforms

dwmmc driver deprecated num-slots and plan to get rid
of it finally. Just move a step to cleanup it from DT.

Cc: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

arch/arm64/boot/dts/exynos/exynos5433-tm2-common.dtsi

@@ -832,7 +832,6 @@
 
 &mshc_0 {
 	status = "okay";
-	num-slots = <1>;
 	mmc-hs200-1_8v;
 	mmc-hs400-1_8v;
 	cap-mmc-highspeed;
@@ -854,7 +853,6 @@
 
 &mshc_2 {
 	status = "okay";
-	num-slots = <1>;
 	cap-sd-highspeed;
 	disable-wp;
 	cd-gpios = <&gpa2 4 GPIO_ACTIVE_HIGH>;

arch/arm64/boot/dts/exynos/exynos7-espresso.dts

@@ -359,7 +359,6 @@
 
 &mmc_0 {
 	status = "okay";
-	num-slots = <1>;
 	cap-mmc-highspeed;
 	mmc-hs200-1_8v;
 	non-removable;
@@ -375,7 +374,6 @@
 
 &mmc_2 {
 	status = "okay";
-	num-slots = <1>;
 	cap-sd-highspeed;
 	card-detect-delay = <200>;
 	clock-frequency = <400000000>;