vala: Fix install conflict when enable multilib.

vala: Fix install conflict when enable multilib.

Error: Transaction test error:
   file /usr/bin/vala-gen-introspect-0.56 conflicts between attempted installs of lib32-vala-0.56.3-r0.armv7ahf_neon and vala-0.56.3-r0.aarch64
   file /usr/bin/vapigen-wrapper conflicts between attempted installs
   of lib32-vala-0.56.3-r0.armv7ahf_neon and vala-0.56.3-r0.aarch64

The differences of vala-gen-introspect-0.56 are as follows:
@@ -2,7 +2,7 @@

 prefix=/usr
 exec_prefix=/usr
-libdir=/usr/lib64
+libdir=/usr/lib
 pkglibdir=${libdir}/vala-0.56

 if [ $# -ne 2 ]

The wrapper isn't used on target so we can simply delete it.

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>