Update language to comply with Android’s inclusive language guidance

Remove usage of term "dummy".

See https://source.android.com/setup/contribute/respectful-code for reference.

Bug: 161896447
Change-Id: I2072c6f373a5e15018f7c534a54f0c330b9f8372
diff --git a/spi/swspi-srv/swspi-srv.c b/spi/swspi-srv/swspi-srv.c
index 86a372b..14f67ad 100644
--- a/spi/swspi-srv/swspi-srv.c
+++ b/spi/swspi-srv/swspi-srv.c
@@ -30,7 +30,7 @@
 
 /*
  * Software SPI buses/devices are connected the following way:
- * First SPI bus is shared. It has a dummy and a test device connected to it.
+ * First SPI bus is shared. It has a fake and a test device connected to it.
  * Second SPI bus is dedicated. Only software loopback device is connected to
  * it.
  */