ipu_common: Let clk_ipu_enable/disable only run on MX51 and MX53

The registers accessed inside clk_ipu_enable/disable are not present on MX6,
so make sure they only run on MX51 and MX53.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
1 file changed