pcmcia: sa1111: simplify clk handing in sa1111_pcmcia_add()

clk_get(dev, NULL) will always refer to the same clock, so it's
pointless calling this multiple times for the same device.  As we no
longer have to worry about the cleanup (via use of devm_clk_get()) we
can simplify sa1111_pcmcia_add() too.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>