mtd: msm_qpic_nand: Fix the opcode used in raw write mode

MTD_OPS_RAW mode should allow the ECC and Spare bytes to be
written from the buffer that user provides. For this, the
opcode[3:0] 0x9 must be programmed into QPIC_NAND_FLASH_CMD
register. But the current code incorrectly uses opcode[3:0]
0x6 which doesn't allow ECC/spare bytes to be written when
ECC is disabled.

Change-Id: I1ae8a8a59e691f275c369a64b93e190fa27a0655
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>