mtd: rawnand: denali: remove unneeded denali_reset_irq() call

This code was added by commit 26d266e1

 ("mtd: nand: denali: fix
raw and oob accessors for syndrome page layout"), but I do not see
sensible reason.

The IRQ flags are correctly reset by denali_cmd_ctrl(), so this code
is unneeded.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>