HID: ishtp-hid-client: Move variable to where it's actually used

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

 In file included from drivers/hid/intel-ish-hid/ishtp-hid.c:11:
     drivers/hid/intel-ish-hid/ishtp-hid.h:24:21: warning: ‘hid_ishtp_guid’ defined but not used [-Wunused-const-variable=]

Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Daniel Drubin <daniel.drubin@intel.com>
Cc: linux-input@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

drivers/hid/intel-ish-hid/ishtp-hid-client.c

@@ -11,6 +11,11 @@
 #include <linux/sched.h>
 #include "ishtp-hid.h"
 
+/* ISH Transport protocol (ISHTP in short) GUID */
+static const guid_t hid_ishtp_guid =
+	GUID_INIT(0x33AECD58, 0xB679, 0x4E54,
+		  0x9B, 0xD9, 0xA0, 0x4D, 0x34, 0xF0, 0xC2, 0x26);
+
 /* Rx ring buffer pool size */
 #define HID_CL_RX_RING_SIZE	32
 #define HID_CL_TX_RING_SIZE	16

drivers/hid/intel-ish-hid/ishtp-hid.h

@@ -20,11 +20,6 @@ extern void (*hid_print_trace)(void *unused, const char *format, ...);
 #define hid_ishtp_trace(client, ...) \
 		(hid_print_trace)(NULL, __VA_ARGS__)
 
-/* ISH Transport protocol (ISHTP in short) GUID */
-static const guid_t hid_ishtp_guid =
-	GUID_INIT(0x33AECD58, 0xB679, 0x4E54,
-		  0x9B, 0xD9, 0xA0, 0x4D, 0x34, 0xF0, 0xC2, 0x26);
-
 /* ISH HID message structure */
 struct hostif_msg_hdr {
 	uint8_t	command; /* Bit 7: is_response */