mtd: spinand: winbond: Add comment about the maximum frequency

Clarify that Winbond octal capable chips may be clocked at up to 166MHz,
which is their absolute maximum.

No per-operation maximum value (captured with a "0" in the table)
involves that in these cases the maximum frequency of the chip applies,
ie. the one commonly described in the DT.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

Author: miquelraynal

drivers/mtd/nand/spi/winbond.c

@@ -32,6 +32,7 @@
 /*
  * "X2" in the core is equivalent to "dual output" in the datasheets,
  * "X4" in the core is equivalent to "quad output" in the datasheets.
+ * Quad and octal capable chips feature an absolute maximum frequency of 166MHz.
  */
 
 static SPINAND_OP_VARIANTS(read_cache_octal_variants,