mtd: msm_qpic_nand: fix extracting oobsize

Extracting the spare size (oobsize) from the NAND IDs table is not correct.
Spare size is part the NAND ID table and that value should be used instead
of calculating it from NAND ID itself.

Change-Id: I494dd868c41859fc7fcb3a472bfbf09aa17f0279
Signed-off-by: Krishna Konda <kkonda@codeaurora.org>