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/waf.bbclass

@@ -3,28 +3,6 @@ DISABLE_STATIC = ""
 
 EXTRA_OECONF_append = " ${PACKAGECONFIG_CONFARGS}"
 
-def get_waf_parallel_make(d):
-    pm = d.getVar('PARALLEL_MAKE')
-    if pm:
-        # look for '-j' and throw other options (e.g. '-l') away
-        # because they might have different meaning in bjam
-        pm = pm.split()
-        while pm:
-            v = None
-            opt = pm.pop(0)
-            if opt == '-j':
-                v = pm.pop(0)
-            elif opt.startswith('-j'):
-                v = opt[2:].strip()
-            else:
-                v = None
-
-            if v:
-                v = min(64, int(v))
-                return '-j' + str(v)
-
-    return ""
-
 python waf_preconfigure() {
     import subprocess
     from distutils.version import StrictVersion
@@ -47,7 +25,7 @@ waf_do_configure() {
 
 do_compile[progress] = "outof:^\[\s*(\d+)/\s*(\d+)\]\s+"
 waf_do_compile()  {
-	${S}/waf build ${@get_waf_parallel_make(d)}
+	${S}/waf build ${@oe.utils.parallel_make_argument(d, '-j%d', limit=64)}
 }
 
 waf_do_install() {