mtd: spi-nor: remove the jedec_id/ext_id

The "id" array contains all the information about the JEDEC and the
manufacturer ID info. This patch removes the jedec_id/ext_id from
flash_info.

Signed-off-by: Huang Shijie <shijie.huang@intel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>