MLK-10547-2 ARM: imx: correct dram pll type

MLK-10547-2 ARM: imx: correct dram pll type

DRAM PLL is a audio/video type PLL, need to correct
it to get correct ops of PLL.

There is a test_div placed before DRAM PLL's gate, so
add this test div clk.

Signed-off-by: Anson Huang <b20788@freescale.com>