scons: Make the USE_KVM variable available in C++.

We need it to determine whether we should expect KVM related parameters
exist in the cirrus graphics device.

diff --git a/SConstruct b/SConstruct
index c811598e3742439a4ca2c03309e997584a71f75a..849585aa768207babccb983d3d3f4d807845c6d4 100755 (executable)
--- a/SConstruct
+++ b/SConstruct
@@ -1135,7 +1135,7 @@ sticky_vars.AddVariables(
 
 # These variables get exported to #defines in config/*.hh (see src/SConscript).
 export_vars += ['USE_FENV', 'SS_COMPATIBLE_FP', 'TARGET_ISA', 'CP_ANNOTATE',
-                'USE_POSIX_CLOCK', 'PROTOCOL', 'HAVE_PROTOBUF',
+                'USE_POSIX_CLOCK', 'USE_KVM', 'PROTOCOL', 'HAVE_PROTOBUF',
                 'HAVE_PERF_ATTR_EXCLUDE_HOST']
 
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