clk: at91: fix masterck name

clk: at91: fix masterck name

commit 65a91e2e597dea62a798a8b771edc44859037e7f upstream.

The master clock is actually named masterck earlier in the driver. Having
"mck" in the parent list means that it can never be selected.

Fixes: 1eabdc2f9dd8 ("clk: at91: add at91sam9x5 PMCs driver")
Fixes: a2038077de9a ("clk: at91: add sama5d2 PMC driver")
Fixes: 084b696bb509 ("clk: at91: add sama5d4 pmc driver")
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>