configure.ac: Build dricommon for gallium swrast

configure.ac: Build dricommon for gallium swrast

When building dri-swrast, use gallium_check_st to set HAVE_COMMON_DRI.
Commit 07f2dee7 added setting of HAVE_COMMON_DRI in gallium_check_st.
But the dri-swrast case did not use gallium_check_st.
So dri/common was still not built.

v2: set HAVE_COMMON_DRI=yes instead of using gallium_check_st

NOTE: This is a candidate for the 9.1 branch.
      (Depends on 7de78ce5 and 07f2dee)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61821
Signed-off-by: Andreas Boll <andreas.boll.dev@gmail.com>