Support fat boot partition with on-device installer

Add patches to support a shorter name "pmOS_i_boot" for the boot partition in the installer OS, that matches fat requirements of 11 characters.

When used with pmbootstrap!2083 (merged), this allows using the on-device installer with fat boot partitions.

main/postmarketos-mkinitfs/APKBUILD

 # Maintainer: Oliver Smith <ollieparanoid@postmarketos.org>
 pkgname=postmarketos-mkinitfs
-pkgver=0.27
+pkgver=0.28
 pkgrel=0
 pkgdesc="Tool to generate initramfs images for postmarketOS"
 url="https://postmarketos.org"
@@ -54,7 +54,7 @@ check() {
 sha512sums="
 4717bf24bd13fd4d90f3ab000ab43f7d61529515de224ebc86458ae709ebe0b5065655457e34f5952126bac6ab45143a91cddb09a8ad2d0a55c5cecd564a0135  00-default.modules
 1a267dd958609263a4f24657f602ac0e4e0c724bf1284adec85e82d05c9b07553085edea5a56f7fa09d1652af232c72d4d39a06858c2a580ff830577b5f37d67  init.sh.in
-393791a7db328d45db7c3b7836ed93208f8b64a6c08a219d31f5a51a167b75ac32407179ae33ef3f72e33fae35c48f676cf526dae190b231d1a766b9a0ad0fb6  init_functions.sh
+daf8bbc02e0dc18dda653d1b25cac985c5ff66568eec7a379857b606843b94f03855d47ded2aff801015ec3c9e2cf90f646dc7deaaef23d373c2ff2b9bbfa435  init_functions.sh
 54c8ea6c4b5313c0ca82bbc40498a35d4b5cbcdbf950dc01b5025238ea6b8caa2f9a9ee57a269fb78673fbcac186c33243188458ecda45deb3354d5d8a77fdfe  mkinitfs.sh
 6b8de5dc13aef9c8090bc4e307b142887e4e3bf1851fe498845be64f7d1ba65d243c1bcb29fbd1b108be2a5067349be1461838573505c9d23e06a680265a4ec3  mkinitfs_functions.sh
 c7a3c33daeb12b33ac72207191941c4d634f15c22958273b52af381a70ebaba1d3a9299483f0c447d9e66c560151fe7b9588bb4bbef2c8914f83185984ee4622  mkinitfs_test.sh