HID: pxrc: constify fixed up report descriptor

Now that the HID core can handle const report descriptors,
constify them where possible.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20240828-hid-const-fixup-2-v1-10-663b9210eb69@weissschuh.net
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>

Author: t-8ch

drivers/hid/hid-pxrc.c

@@ -17,7 +17,7 @@ struct pxrc_priv {
 	bool alternate;
 };
 
-static __u8 pxrc_rdesc_fixed[] = {
+static const __u8 pxrc_rdesc_fixed[] = {
 	0x05, 0x01,        // Usage Page (Generic Desktop Ctrls)
 	0x09, 0x04,        // Usage (Joystick)
 	0xA1, 0x01,        // Collection (Application)