Randy suggested to print out the symbol type in gconfig.

Note this change does more than Randy's suggestion, that it also
affects menuconfig and "make config".

  │ Symbol: BLOCK [=y]
  │ Type  : boolean
  │ Prompt: Enable the block layer
  │   Defined at block/Kconfig:4
  │   Depends on: EMBEDDED [=n]
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>