main/postmarketos-mkinitfs: support mounting with UUIDs

Tested it on my device with altered partition labels

main/postmarketos-mkinitfs/APKBUILD

@@ -2,7 +2,7 @@
 # Co-Maintainer: Clayton Craft <clayton@craftyguy.net>
 pkgname=postmarketos-mkinitfs
 pkgver=1.4.1
-pkgrel=10
+pkgrel=11
 pkgdesc="Tool to generate initramfs images for postmarketOS"
 url="https://postmarketos.org"
 depends="
@@ -72,5 +72,5 @@ sha512sums="
 f827acb0a10c0e5c1631f1b712e91fde7eb4ade0f1174eb2ef1754018bf4518ea1ad3229fd335c25fb0c6fe46ae20890f5cf43e58c8143ae17b5ab9bb36f0199  postmarketos-mkinitfs-1.4.1.tar.gz
 20f110337113e8de8999cf2a064a93fea36821d5c216bfa4ba46ec1f83825638262b92fd7be29eee0a85a54a108b7315a96cbe30da8ae4419f54c2ed53bb08c7  00-default.modules
 ccdceaa710d97d6f57d8d66bfcbec448486d08083341712303f62123039f729229b88528308e411a308a2b90b81b60de89fe91143a6facbb11cbc9b4055eeaec  init.sh
-cefebaf04f68c2787fad787458dd4533c507a15139e666d1985dba17dc55067c6246db14d174a5c302c2a9e077756b2ce6cccc59f7cabca11c2b1c44b6a2feb5  init_functions.sh
+9425c9ae5bcef0f261751c4f0cd8fbd634b2f06aefd34c3f2e9a95ea50abaa65611f1cebc0d3533e721f7610f9b37a7f4c26aa7938a9880fcb8e9902839f0c84  init_functions.sh
 "