sh: hw_breakpoint: Add missing forward declaration for arch_bp_generic_fields()

arch/sh/kernel/hw_breakpoint.c:135:5: warning: no previous prototype for ‘arch_bp_generic_fields’ [-Wmissing-prototypes]

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/566af354bf51ddc38e9eb95eac51ec00c4e42024.1709326528.git.geert+renesas@glider.be
Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>

Author: geertu

arch/sh/include/asm/hw_breakpoint.h

@@ -52,6 +52,8 @@ struct pmu;
 
 /* arch/sh/kernel/hw_breakpoint.c */
 extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
+extern int arch_bp_generic_fields(int sh_len, int sh_type, int *gen_len,
+				  int *gen_type);
 extern int hw_breakpoint_arch_parse(struct perf_event *bp,
 				    const struct perf_event_attr *attr,
 				    struct arch_hw_breakpoint *hw);