Remove obsolete references to ustruct

Author: dhalbert

adafruit_ra8875/ra8875.py

@@ -27,16 +27,13 @@
 """
 
 # imports
+import struct
 import time
+
 from digitalio import Direction
 from adafruit_bus_device import spi_device
 import adafruit_ra8875.registers as reg
 
-try:
-    import struct
-except ImportError:
-    import ustruct as struct
-
 __version__ = "0.0.0-auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_RA8875.git"