device-samsung-i9100: use ttySAC2 for getty shell (MR 4861)

Unfortunately we cannot get to a getty shell unless we also run:
  setenv SWITCH_SEL 3
from the SBL shell.  Furthermore, actually getting kernel output
requires setting console=ttySAC2,115200.

SWITCH_SEL might be related to the "MUIC" of the device, but the
variable also controls whether or not it is possible to get serial
output from pads on main board, and seems weird that those pads are
affected by MUIC (unless pads are also behind MUIC, but seems like
that would be very annoying when developing the device)

See also initial MR where mainline support for i9100 was added, where
serial output is also discussed:
https://gitlab.com/postmarketOS/pmaports/-/merge_requests/1598#how-to-get-serial-output
[ci:skip-build]: already built successfully in CI

device/testing/device-samsung-i9100/APKBUILD

@@ -1,7 +1,7 @@
 # Reference: <https://postmarketos.org/devicepkg>
 pkgname=device-samsung-i9100
-pkgver=5
-pkgrel=2
+pkgver=6
+pkgrel=0
 pkgdesc="Samsung Galaxy SII"
 url="https://postmarketos.org"
 arch="armv7"
@@ -66,7 +66,7 @@ media_pipeline() {
 }
 
 sha512sums="
-f45899db647fd338359858114d6e8eeeeb40c989afb248d7bb9de102993087ad58ffdedbb65f57085d5b1e4a6d4e382017a5b456619bb4351e8731dca593055c  deviceinfo
+927e2cbed184ce2999a25bfb98a7fc19299350a7d8c4d5531d875ea3a5e52609bf6827ecbbdd35a011b8e9026aa9d01914ded2358fe96ac53deeae3f9f117c53  deviceinfo
 089635daddd88eec35451bfe98dc3713035e3623c896dd21305b990ecf422e8fbb54e010cf347919bbb3a7385f639ab119280477fe0783df3228168d97d96fc6  90-android-touch-dev.rules
 d3f06476be583f095189557e5269866cfc9346ddbf8d78267d7562fad7f5eca6b09b81fd08cd9690ecf88105bafe8f3ebd9136b68ab5cdaa8bfff740a8bdf3d2  media-pipeline.initd
 "

device/testing/device-samsung-i9100/deviceinfo

@@ -8,7 +8,7 @@ deviceinfo_codename="samsung-i9100"
 deviceinfo_year="2011"
 deviceinfo_append_dtb_mainline="true"
 deviceinfo_dtb_mainline="exynos4210-i9100"
-deviceinfo_external_storage="true"
+deviceinfo_getty="ttySAC2;115200"
 deviceinfo_flash_method="heimdall-isorec"
 deviceinfo_arch="armv7"
 deviceinfo_mesa_driver_mainline="exynos"
@@ -17,6 +17,7 @@ deviceinfo_mesa_driver_mainline="exynos"
 deviceinfo_gpu_accelerated="true"
 deviceinfo_chassis="handset"
 deviceinfo_keyboard="false"
+deviceinfo_external_storage="true"
 deviceinfo_screen_width="480"
 deviceinfo_screen_height="800"