mx25/clocks: match esdhc-clocks to platform device

So the correct clock will be taken for each of the two independent
controllers.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Eric Bénard <eric@eukrea.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>