Up the limit of HID devices from 4 to 16

This allows the use more HID devices. For example the use of
a logitech unify dongle for a wireless keyboard/mouse combo and then
a wired keyboard with a mouse attached to the keyboard's hub. Plus
whatever composite devices are part of the keyboard and/or mouse.

Author: morio

include/tusb_config.h

@@ -79,7 +79,7 @@
 #define CFG_TUH_HUB                 7
 // max device support (excluding hub device)
 #define CFG_TUH_DEVICE_MAX          14 // hub typically has 4 ports
-#define CFG_TUH_HID                 4 // typical keyboard + mouse device can have 3-4 HID interfaces
+#define CFG_TUH_HID                 16 // typical keyboard + mouse device can have 3-4 HID interfaces
 #define CFG_TUH_MSC                 0
 
 #define CFG_TUH_HID_EPIN_BUFSIZE    64

lib/libpico.a

@@ -79,7 +79,7 @@
 #define CFG_TUH_HUB                 7
 // max device support (excluding hub device)
 #define CFG_TUH_DEVICE_MAX          14 // hub typically has 4 ports
-#define CFG_TUH_HID                 4 // typical keyboard + mouse device can have 3-4 HID interfaces
+#define CFG_TUH_HID                 16 // typical keyboard + mouse device can have 3-4 HID interfaces
 #define CFG_TUH_MSC                 0
 
 #define CFG_TUH_HID_EPIN_BUFSIZE    64