bios: fix log message for gpio mux

Since the function does not know which side the mux will take, the log
message can be generic.

Change-Id: I31e96fd230bc13967252a8344a42f0b341076a9d
Signed-off-by: Alexander Hansen <alexander.hansen@9elements.com>
diff --git a/bios/spi_device.cpp b/bios/spi_device.cpp
index 7372c40..e6917b5 100644
--- a/bios/spi_device.cpp
+++ b/bios/spi_device.cpp
@@ -235,7 +235,7 @@
     ::gpiod::line_request config{"", ::gpiod::line_request::DIRECTION_OUTPUT,
                                  0};
 
-    debug("[gpio] requesting gpios to mux SPI to BMC");
+    debug("requesting gpios for mux");
 
     auto lineBulk = std::make_unique<::gpiod::line_bulk>(lines);