scs: Remove references to asm/scs.h from core code

asm/scs.h is no longer needed by the core code, so remove a redundant
header inclusion and update the stale Kconfig text.
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

arch/Kconfig

@@ -537,8 +537,8 @@ config ARCH_SUPPORTS_SHADOW_CALL_STACK
 	bool
 	help
 	  An architecture should select this if it supports Clang's Shadow
-	  Call Stack, has asm/scs.h, and implements runtime support for shadow
-	  stack switching.
+	  Call Stack and implements runtime support for shadow stack
+	  switching.
 
 config SHADOW_CALL_STACK
 	bool "Clang Shadow Call Stack"

kernel/scs.c

@@ -10,7 +10,6 @@
 #include <linux/scs.h>
 #include <linux/slab.h>
 #include <linux/vmstat.h>
-#include <asm/scs.h>
 
 static struct kmem_cache *scs_cache;