i2c: imx: Remove clk_get_rate for each transfer again

As clk_get_rate() also keeps the clk prepare lock which can lead into a
deadlock. It was removed upstream with this commit:
(90ad2cbe) i2c: imx: use clk notifier for rate changes

But it has been readded again with:
(d2561688) MLK-20368 i2c-imx: Coverity: fix divide by zero warning

The commit message does not explain why it was readded. It is not needed
as the clk notifier is used. Removed it again.

REFERENCE: https://github.com/nxp-imx/linux-imx/pull/21

drivers/i2c/busses/i2c-imx.c

@@ -705,10 +705,6 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx, bool atomic)
 
 	dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
 
-	result = i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk));
-	if (result)
-		return result;
-
 	imx_i2c_write_reg(i2c_imx->ifdr, i2c_imx, IMX_I2C_IFDR);
 	/* Enable I2C controller */
 	imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);