mtd: rawnand: denali: clean up coding style

Eliminate the following reports from 'scripts/checkpatch.pl --strict'.

  CHECK: Prefer kernel type 'u8' over 'uint8_t'
  CHECK: Prefer kernel type 'u32' over 'uint32_t'
  CHECK: Alignment should match open parenthesis

I slightly changed denali_check_erased_page() to shorten it.

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