gitignore: ignore shared objects

Many arches make shared objects for VDSOs.  Generally exclude them.
Signed-off-by: NBrian Gerst <bgerst@didntduck.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

.gitignore

@@ -10,6 +10,7 @@
 *.a
 *.s
 *.ko
+*.so
 *.mod.c
 
 #

arch/x86_64/ia32/.gitignore

-vsyscall*.so