x86: update .gitignore entries

vdso / vsycall create .so.dbg files now.
Add *.so.dbg to the main .ignore file

Exclude the compile time created boot directory in arch/x86_64 as well

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/.gitignore b/.gitignore
index 22fb8fa..8d14531 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,6 +12,7 @@
 *.s
 *.ko
 *.so
+*.so.dbg
 *.mod.c
 *.i
 *.lst