device-samsung-m3: set getty and flash kernel on update (MR 4719)

Serial shell on ttySAC2, and kernel upgrades, work well for i9305/m3,
just like for i9300/m0.

[ci:skip-build]: Already built successfully in CI.

device/testing/device-samsung-m3/APKBUILD

@@ -1,8 +1,8 @@
 # Reference: <https://postmarketos.org/devicepkg>
 pkgname=device-samsung-m3
 pkgdesc="Samsung Galaxy S III LTE"
-pkgver=6.1
-pkgrel=3
+pkgver=6.2
+pkgrel=0
 url="https://postmarketos.org"
 license="MIT"
 arch="armv7"
@@ -12,6 +12,7 @@ depends="
 	linux-postmarketos-exynos4
 	mkbootimg
 	postmarketos-base
+	postmarketos-update-kernel
 	soc-samsung-exynos4412-haptics
 	"
 makedepends="devicepkg-dev"
@@ -51,7 +52,7 @@ nonfree_firmware() {
 }
 
 sha512sums="
-d2ed2eedd223854766121058273a3a90b1672dbb95d0072b56100c01196cbe5ee96049c3b646b9b2f60af1254743ef4c4006e6275f407d582ec012e7bd383f71  deviceinfo
+4674bb08bce234140144a6cb5f22eb7095367bf01b8976b33f122c78459b79f181d39acd9fa0a15f183a43729d0838143d4027665fa753c38d04dce13e3eacec  deviceinfo
 caa81e8ab6753c0ca24c22fb6742288765dfbf2469b8b8c35c5789edfcee546ef1c3b14ad6e540c417f434258399300f17d312b58157635eafab134587ef94cc  Midas.conf
 21f64c9104ec5780fffde8ba7ce57583592469694d07dd5e2de4173d7c9f99ba57fb28bb5bcfbbce921be9c4ead9d31980e948533162fe12424c2037145debb1  HiFi.conf
 56a2bdffc273cb0a581192e65378ff50e71c7bc8a696af7d5e7c165a53c005aae104c4514c68afb668454c5a94ce78bd509f8a40e3401d67e16636b1ed81d051  modules-load.conf

device/testing/device-samsung-m3/deviceinfo

@@ -8,7 +8,9 @@ deviceinfo_codename="samsung-m3"
 deviceinfo_year="2012"
 deviceinfo_append_dtb="true"
 deviceinfo_dtb="exynos4412-i9305"
+deviceinfo_getty="ttySAC2;115200"
 deviceinfo_arch="armv7"
+deviceinfo_flash_kernel_on_update="true"
 
 # Device related
 deviceinfo_gpu_accelerated="true"