nds32: remove redundant kernel-space generic-y

This commit removes redundant generic-y defines in
arch/nds32/include/asm/Kbuild.

[1] It is redundant to define the same generic-y in both
    arch/$(ARCH)/include/asm/Kbuild and
    arch/$(ARCH)/include/uapi/asm/Kbuild.

    Remove the following generic-y:

      bitsperlong.h
      bpf_perf_event.h
      errno.h
      fcntl.h
      ioctl.h
      ioctls.h
      mman.h
      shmbuf.h
      stat.h

[2] It is redundant to define generic-y when arch-specific
    implementation exists in arch/$(ARCH)/include/asm/*.h

    Remove the following generic-y:

      ftrace.h
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

arch/nds32/include/asm/Kbuild

 generic-y += asm-offsets.h
 generic-y += atomic.h
 generic-y += bitops.h
-generic-y += bitsperlong.h
-generic-y += bpf_perf_event.h
 generic-y += bug.h
 generic-y += bugs.h
 generic-y += checksum.h
@@ -16,17 +14,12 @@ generic-y += div64.h
 generic-y += dma.h
 generic-y += dma-mapping.h
 generic-y += emergency-restart.h
-generic-y += errno.h
 generic-y += exec.h
 generic-y += export.h
 generic-y += fb.h
-generic-y += fcntl.h
-generic-y += ftrace.h
 generic-y += gpio.h
 generic-y += hardirq.h
 generic-y += hw_irq.h
-generic-y += ioctl.h
-generic-y += ioctls.h
 generic-y += irq.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
@@ -38,7 +31,6 @@ generic-y += limits.h
 generic-y += local.h
 generic-y += local64.h
 generic-y += mm-arch-hooks.h
-generic-y += mman.h
 generic-y += parport.h
 generic-y += pci.h
 generic-y += percpu.h
@@ -46,9 +38,7 @@ generic-y += preempt.h
 generic-y += sections.h
 generic-y += segment.h
 generic-y += serial.h
-generic-y += shmbuf.h
 generic-y += sizes.h
-generic-y += stat.h
 generic-y += switch_to.h
 generic-y += timex.h
 generic-y += topology.h