arm64/kernel: remove duplicate include in process.c

Remove all but the first include of linux/sched.h from process.c
Reported-by: NZeal Robot <zealci@zte.com.cn>
Signed-off-by: NLv Ruyi <lv.ruyi@zte.com.cn>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210902011126.29828-1-lv.ruyi@zte.com.cnSigned-off-by: NCatalin Marinas <catalin.marinas@arm.com>

arch/arm64/kernel/process.c

@@ -18,7 +18,6 @@
 #include <linux/mman.h>
 #include <linux/mm.h>
 #include <linux/nospec.h>
-#include <linux/sched.h>
 #include <linux/stddef.h>
 #include <linux/sysctl.h>
 #include <linux/unistd.h>