File locking refactored (#631)

Remove FileMutex and wire locking into driver subsystems.

TactilityKernel/source/drivers/spi_controller.cpp

@@ -22,6 +22,22 @@ error_t spi_controller_unlock(Device* device) {
     return SPI_DRIVER_API(driver)->unlock(device);
 }
 
+error_t spi_controller_lock_bus_of(Device* device) {
+    Device* parent = device_get_parent(device);
+    if (parent == nullptr || device_get_type(parent) != &SPI_CONTROLLER_TYPE) {
+        return ERROR_NONE;
+    }
+    return spi_controller_lock(parent);
+}
+
+void spi_controller_unlock_bus_of(Device* device) {
+    Device* parent = device_get_parent(device);
+    if (parent == nullptr || device_get_type(parent) != &SPI_CONTROLLER_TYPE) {
+        return;
+    }
+    spi_controller_unlock(parent);
+}
+
 const DeviceType SPI_CONTROLLER_TYPE {
     .name = "spi-controller"
 };