device-xiaomi-scorpio: Add RMTFS to runlevel default

This fixes random crashing caused by modem and ADSP on xiaomi-scorpio.

device/community/device-xiaomi-scorpio/APKBUILD

@@ -4,7 +4,7 @@
 pkgname=device-xiaomi-scorpio
 pkgdesc="Xiaomi Mi Note 2"
 pkgver=2
-pkgrel=0
+pkgrel=1
 url="https://postmarketos.org"
 license="MIT"
 arch="aarch64"
@@ -44,6 +44,7 @@ nonfree_firmware() {
 		linux-firmware-qca
 		soc-qcom-msm8996-nonfree-firmware
 		"
+	install="$subpkgname.post-install"
 	mkdir "$subpkgdir"
 }