riscv: Fix spelling mistake "SPARSEMEM" to "SPARSMEM"

There is a spelling mistake when SPARSEMEM Kconfig copy.

Fixes: a5406a7 ("riscv: Correct SPARSEMEM configuration")
Cc: stable@vger.kernel.org
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

arch/riscv/Kconfig

@@ -153,7 +153,7 @@ config ARCH_FLATMEM_ENABLE
 config ARCH_SPARSEMEM_ENABLE
  def_bool y
  depends on MMU
- select SPARSEMEM_STATIC if 32BIT && SPARSMEM
+ select SPARSEMEM_STATIC if 32BIT && SPARSEMEM
  select SPARSEMEM_VMEMMAP_ENABLE if 64BIT
 
 config ARCH_SELECT_MEMORY_MODEL