src/soc/nvidia: Remove unused <stdlib.h>

Change-Id: I404d149cd1052fa0aef233bd0e0867524c738477
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37382
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/nvidia/tegra210/clock.c

@@ -18,7 +18,6 @@
 #include <assert.h>
 #include <console/console.h>
 #include <delay.h>
-#include <stdlib.h>
 #include <soc/addressmap.h>
 #include <soc/clk_rst.h>
 #include <soc/clock.h>