According to datasheet mul mask is on bits 31..24.

Fixes: a436c2a4 ("clk: at91: add sam9x60 PLL driver")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/1595403506-8209-4-git-send-email-claudiu.beznea@microchip.comSigned-off-by: Stephen Boyd <sboyd@kernel.org>