platform: x86: intel_scu_ipc: Replace mdelay with usleep_range in intel_scu_ipc_i2c_cntrl

intel_scu_ipc_i2c_cntrl() calls mutex_lock(), which indicates
this function is not called in atomic context.

Despite never getting called from atomic context,
intel_scu_ipc_i2c_cntrl() calls mdelay to busily wait.
This is not necessary and can be replaced with usleep_range to
avoid busy waiting.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.
Signed-off-by: NJia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/platform/x86/intel_scu_ipc.c

@@ -584,11 +584,11 @@ int intel_scu_ipc_i2c_cntrl(u32 addr, u32 *data)
 	if (cmd == IPC_I2C_READ) {
 		writel(addr, scu->i2c_base + IPC_I2C_CNTRL_ADDR);
 		/* Write not getting updated without delay */
-		mdelay(1);
+		usleep_range(1000, 2000);
 		*data = readl(scu->i2c_base + I2C_DATA_ADDR);
 	} else if (cmd == IPC_I2C_WRITE) {
 		writel(*data, scu->i2c_base + I2C_DATA_ADDR);
-		mdelay(1);
+		usleep_range(1000, 2000);
 		writel(addr, scu->i2c_base + IPC_I2C_CNTRL_ADDR);
 	} else {
 		dev_err(scu->dev,