build: remove redundant libs from pkgconfig

As explained in drivers/meson.build,
"
  For the find_library() case (but not with dependency()) we also
  need to specify the "-l" flags in pkgconfig_extra_libs variable
  too, so that it can be reflected in the pkgconfig output for
  static builds.
"

The commit e30b4e5 ("build: improve dependency handling")
must be followed up with this one in order to remove more
occurences of pkgconfig_extra_libs redundant with use of dependency().

Fixes: f1debd7 ("net/af_xdp: introduce AF_XDP PMD")
Fixes: 3c32e89 ("compress/isal: add skeleton ISA-L compression PMD")
Cc: stable@dpdk.org

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Luca Boccassi <bluca@debian.org>

drivers/compress/isal/meson.build

@@ -10,6 +10,5 @@ endif
 deps += 'bus_vdev'
 sources = files('isal_compress_pmd.c', 'isal_compress_pmd_ops.c')
 ext_deps += dep
-pkgconfig_extra_libs += '-lisal'
 
 allow_experimental_apis = true

drivers/net/af_xdp/meson.build

@@ -10,7 +10,6 @@ endif
 
 if bpf_dep.found() and cc.has_header('bpf/xsk.h') and cc.has_header('linux/if_xdp.h')
 	ext_deps += bpf_dep
-	pkgconfig_extra_libs += '-lbpf'
 else
 	build = false
 	reason = 'missing dependency, "libbpf"'