arch: remove dangling asm-generic wrappers

These generic-y defines do not have the corresponding generic header
in include/asm-generic/, so they are definitely invalid.

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

arch/riscv/include/asm/Kbuild

@@ -1,7 +1,6 @@
 generic-y += bugs.h
 generic-y += checksum.h
 generic-y += compat.h
-generic-y += cputime.h
 generic-y += device.h
 generic-y += div64.h
 generic-y += dma.h
@@ -11,7 +10,6 @@ generic-y += emergency-restart.h
 generic-y += exec.h
 generic-y += fb.h
 generic-y += hardirq.h
-generic-y += hash.h
 generic-y += hw_irq.h
 generic-y += irq_regs.h
 generic-y += irq_work.h
@@ -21,10 +19,8 @@ generic-y += kvm_para.h
 generic-y += local.h
 generic-y += local64.h
 generic-y += mm-arch-hooks.h
-generic-y += mutex.h
 generic-y += percpu.h
 generic-y += preempt.h
-generic-y += scatterlist.h
 generic-y += sections.h
 generic-y += serial.h
 generic-y += shmparam.h