targets/tec0117: move SerialFlashManager import to flash function.

litex_boards/targets/tec0117.py

@@ -22,8 +22,6 @@ from litex.soc.cores.led import LedChaser
 
 from litex_boards.platforms import tec0117
 
-from spiflash.serialflash import SerialFlashManager
-
 kB = 1024
 mB = 1024*kB
 
@@ -73,6 +71,7 @@ class BaseSoC(SoCCore):
 # Flash --------------------------------------------------------------------------------------------
 
 def flash(offset, path):
+    from spiflash.serialflash import SerialFlashManager
     platform = tec0117.Platform()
     flash = platform.request("spiflash", 0)
     bus = platform.request("spiflash", 1)