mtd: rawnand: qcom: avoid writing to obsolete register

QPIC_EBI2_ECC_BUF_CFG register got obsolete from QPIC V2.0 onwards.
Avoid writing this register if QPIC version is V2.0 or newer.

Signed-off-by: Md Sadre Alam <mdalam@codeaurora.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/1623134916-562-1-git-send-email-mdalam@codeaurora.org