rdma-core: remove the installation of dbg packages

Clean dbg packages from installation because they aren't
necessary.

Test Plan:
 Pass: build-image
 Pass: install iso OK on target, and check that those packages aren't
       installed.

Story: 2010643
Task: 47628

Signed-off-by: Li Zhou <li.zhou@windriver.com>
Change-Id: I58c99a1925449eb2849b600a6b2708e3723b4fe3

debian_iso_image.inc

@@ -95,19 +95,14 @@ ibverbs-providers
 ibverbs-utils
 infiniband-diags
 #libibmad-dev  # not used
-libibmad5-dbg
 libibmad5
 #libibnetdisc-dev  # not used
-libibnetdisc5-dbg
 libibnetdisc5
 #libibumad-dev  # not used
-libibumad3-dbg
 libibumad3
 #libibverbs-dev  # not used
-libibverbs1-dbg
 libibverbs1
 #librdmacm-dev  # not used
-librdmacm1-dbg
 librdmacm1
 python3-pyverbs
 rdma-core