utils.py: add parallel make helpers

The code to extract the integer number of parallel build threads and
construct a new argument from them has started to be copied in multiple
locations, so create two new helper utilities to aid recipes.

The first helper (parallel_make()) extracts the integer number of
parallel build threads from PARALLEL_MAKE. The second
(parallel_make_argument()) does the same and then puts the result back
into a format string, optionally clamping it to some maximum value.

Additionally, rework the oe-core recipes that were manually doing this
to use the new helper utilities.

(From OE-Core rev: ccd1142d22b31ed85d8823b1bc9e11ccfd72b61f)

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/go.bbclass

@@ -1,23 +1,6 @@
 inherit goarch ptest
 
-def get_go_parallel_make(d):
-    pm = (d.getVar('PARALLEL_MAKE') or '').split()
-    # look for '-j' and throw other options (e.g. '-l') away
-    # because they might have a different meaning in golang
-    while pm:
-        opt = pm.pop(0)
-        if opt == '-j':
-            v = pm.pop(0)
-        elif opt.startswith('-j'):
-            v = opt[2:].strip()
-        else:
-            continue
-
-        return '-p %d' % int(v)
-
-    return ""
-
-GO_PARALLEL_BUILD ?= "${@get_go_parallel_make(d)}"
+GO_PARALLEL_BUILD ?= "${@oe.utils.parallel_make_argument(d, '-p %d')}"
 
 GOROOT_class-native = "${STAGING_LIBDIR_NATIVE}/go"
 GOROOT_class-nativesdk = "${STAGING_DIR_TARGET}${libdir}/go"