s390/ftrace: enforce DYNAMIC_FTRACE if FUNCTION_TRACER is selected

We have too many combinations for function tracing. Lets simply stick to
the most advanced option, so we don't have to care of other combinations.

This means we always select DYNAMIC_FTRACE if FUNCTION_TRACER is selected.

In the s390 Makefile also remove CONFIG_FTRACE_SYSCALLS since that
functionality got moved to architecture independent code in the meantime.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/ftrace.c

@@ -17,8 +17,6 @@
 #include <asm/asm-offsets.h>
 #include "entry.h"
 
-#ifdef CONFIG_DYNAMIC_FTRACE
-
 void ftrace_disable_code(void);
 void ftrace_enable_insn(void);
 
@@ -142,8 +140,6 @@ int __init ftrace_dyn_arch_init(void)
 	return 0;
 }
 
-#endif /* CONFIG_DYNAMIC_FTRACE */
-
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 /*
  * Hook the return address and push it in the stack of return addresses
@@ -169,7 +165,6 @@ out:
 	return parent;
 }
 
-#ifdef CONFIG_DYNAMIC_FTRACE
 /*
  * Patch the kernel code at ftrace_graph_caller location. The instruction
  * there is branch relative and save to prepare_ftrace_return. To disable
@@ -219,5 +214,4 @@ int ftrace_disable_ftrace_graph_caller(void)
 }
 
 #endif /* CONFIG_64BIT */
-#endif /* CONFIG_DYNAMIC_FTRACE */
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */