span: switch to std

Reduce the dependency on stdplus' version of span now that we are using
C++20 and use the one out of the STL instead.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I040ba1796d6f278353fbc990ea6b62314927951e
diff --git a/tools/pci.cpp b/tools/pci.cpp
index 150095f..8403771 100644
--- a/tools/pci.cpp
+++ b/tools/pci.cpp
@@ -30,6 +30,7 @@
 #include <stdplus/handle/managed.hpp>
 
 #include <cstring>
+#include <span>
 #include <system_error>
 
 namespace host_tool
@@ -104,7 +105,7 @@
     }
 }
 
-void PciAccessBridge::write(const stdplus::span<const std::uint8_t> data)
+void PciAccessBridge::write(const std::span<const std::uint8_t> data)
 {
     if (data.size() > dataLength)
     {