device-raspberry-pi: fix linux-rpi2 dependency (MR 5721)

The package was renamed/replaced in Alpine with:
https://gitlab.alpinelinux.org/alpine/aports/-/commit/6f4fa0525cecbd37a6a9d49c64e545348f521ed7

device/testing/device-raspberry-pi/APKBUILD

@@ -2,7 +2,7 @@
 pkgname=device-raspberry-pi
 pkgdesc="Raspberry Pi"
 pkgver=1
-pkgrel=0
+pkgrel=1
 url="https://postmarketos.org"
 license="MIT"
 arch="armhf"
@@ -44,7 +44,7 @@ kernel_rpi() {
 
 kernel_rpi2() {
 	pkgdesc="Kernel for the Raspberry Pi 2 (from Alpine, depends on non free firmware!)"
-	depends="$pkgname linux-rpi2"
+	depends="$pkgname linux-rpi"
 	install="$subpkgname.post-install $subpkgname.post-upgrade"
 	mkdir "$subpkgdir"
 }