spi: sun4i: fix typos in comments

Various spelling mistakes in comments.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <[e-mail]>
Acked-by: Chen-Yu Tsai <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/spi/spi-sun4i.c

···
 	 * SPI_CLK = MOD_CLK / (2 ^ (cdr + 1))
 	 * Or we can use CDR2, which is calculated with the formula:
 	 * SPI_CLK = MOD_CLK / (2 * (cdr + 1))
-	 * Wether we use the former or the latter is set through the
+	 * Whether we use the former or the latter is set through the
 	 * DRS bit.
 	 *
 	 * First try CDR2, and if we can't reach the expected