mtd: nand: denali: remove unused struct member totalblks, blksperchip

The denali->blksperchip is set, but not referenced any more.  The
denali->totalblks is used only for calculating denali->blksperchip.
Both of them are unneeded.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>