ARM: imx: rename imx6q_set_int_mem_clk_lpm() function

Let's rename the function imx6q_set_int_mem_clk_lpm()
to imx6_set_int_mem_clk_lpm() since it's actually
common for all i.MX6 SoCs.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>