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

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>