core/linux-aarch64 to 6.8.1-2

Use an alternative trigger for mkinitcpio.  One user reported broken
bluetooth fw on RPi4B due to the chose of the old target[1].

1. https://archlinuxarm.org/forum/viewtopic.php?f=15&t=16803

core/linux-aarch64/PKGBUILD

@@ -9,7 +9,7 @@ _srcname=linux-6.8
 _kernelname=${pkgbase#linux}
 _desc="AArch64 multi-platform"
 pkgver=6.8.1
-pkgrel=1
+pkgrel=2
 arch=('aarch64')
 url="http://www.kernel.org/"
 license=('GPL2')
@@ -98,10 +98,10 @@ _package() {
   sed "${_subst}" ../linux.preset |
     install -Dm644 /dev/stdin "${pkgdir}/etc/mkinitcpio.d/${pkgbase}.preset"
 
-  # rather than use another hook (90-linux.hook) rely on kmod's 90-mkinitcpio-install.hook
+  # rather than use another hook (90-linux.hook) rely on mkinitcpio's 90-mkinitcpio-install.hook
   # which avoids a double run of mkinitcpio that can occur
-  install -d "${pkgdir}/usr/lib/firmware/"
-  touch "${pkgdir}/usr/lib/firmware/$(<version)"
+  install -d "${pkgdir}/usr/lib/initcpio/"
+  echo "dummy file to trigger mkinitcpio to run" > "${pkgdir}/usr/lib/initcpio/$(<version)"
 }
 
 _package-headers() {