USB-Cypress: Lock sleep when USB is initialized

None of the USB drivers currently support entering deep sleep mode
while USB is active. To protect USB from malfunctioning lock deep
sleep in USBPhyHw::init.This is done for similar

This was done for all other implementations as part of
8ffbe5c6033

Author: hugueskamba

targets/TARGET_Cypress/TARGET_PSOC6/cy_usb_phy.cpp

@@ -17,6 +17,7 @@
 
 #include "cy_usb_phy_hw.h"
 #include "mbed_assert.h"
+#include "mbed_power_mgmt.h"
 
 #if defined(DEVICE_USBDEVICE)
 
@@ -64,6 +65,10 @@ void USBPhyHw::init(USBPhyEvents *events)
     // Initialize instance to access class data
     instance = this;
 
+    if (this->events == NULL) {
+        sleep_manager_lock_deep_sleep();
+    }
+
     // Store events
     instance->events = events;
 
@@ -176,6 +181,12 @@ void USBPhyHw::usb_dev_execute_ep_callbacks(void)
 void USBPhyHw::deinit()
 {
     cyhal_usb_dev_free(&obj);
+
+    if (events != NULL) {
+        sleep_manager_unlock_deep_sleep();
+    }
+
+    events = NULL;
 }
 
 bool USBPhyHw::powered()