clk: at91: remove the checking of parent_name

clk: at91: remove the checking of parent_name

There is no need to check parent_name variable while assigning it to
init.parent_names. parent_name variable is already checked at
the beginning of at91_clk_register_peripheral() function.

Fixes: 86ec23ac7239a ("clk: at91: add PMC peripheral clocks")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/1598338751-20607-2-git-send-email-claudiu.beznea@microchip.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>