mtd: nand: qcom: reorganize nand page read

Each NAND page consist of multiple codewords. Following is
sequence for NAND page read according to hardware guide.

1. Program Power-up configuration, page row, page column
address and flash configuration registers.
2. Write NAND_FLASH_CMD followed by NANC_EXEC_CMD for each
codeword.
3. Read NAND_FLASH_STATUS for each codeword.

The step 1 should be done once for each page and step 2,3 should
be done for each codeword.

Currently, all the 3 steps are being done for each codeword which
is wrong. Now this patch reorganizes read page functions to
configure page specific register once and per codeword specific
registers for each NAND ECC step.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>