Input: elan_i2c_core - move header inclusion inside

The same clause as its use.

Fixes the following W=1 kernel build warning(s):

 include/linux/input/elan-i2c-ids.h:26:36: warning: ‘elan_acpi_id’ defined but not used [-Wunused-const-variable=]
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201112104420.GG1997862@dellSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/mouse/elan_i2c_core.c

@@ -34,7 +34,6 @@
 #include <linux/completion.h>
 #include <linux/of.h>
 #include <linux/property.h>
-#include <linux/input/elan-i2c-ids.h>
 #include <linux/regulator/consumer.h>
 #include <asm/unaligned.h>
 
@@ -1413,6 +1412,7 @@ static const struct i2c_device_id elan_id[] = {
 MODULE_DEVICE_TABLE(i2c, elan_id);
 
 #ifdef CONFIG_ACPI
+#include <linux/input/elan-i2c-ids.h>
 MODULE_DEVICE_TABLE(acpi, elan_acpi_id);
 #endif