clk: imx31: retain early UART clocks during kernel init

static struct clk *clk[clk_max];

static struct clk_onecell_data clk_data;

static struct clk ** const uart_clks[] __initconst = {

	&clk[ipg],

	&clk[uart1_gate],

	&clk[uart2_gate],

	&clk[uart3_gate],

	&clk[uart4_gate],

	&clk[uart5_gate],

	NULL

};

int __init mx31_clocks_init(unsigned long fref)

{

	void __iomem *base;

	mx31_revision();

	clk_disable_unprepare(clk[iim_gate]);

	imx_register_uart_clocks(uart_clks);

	mxc_timer_init(MX31_GPT1_BASE_ADDR, MX31_INT_GPT, GPT_TYPE_IMX31);

	return 0;