testing/mgba: build with sdl2-dev

Tested and works with homebrew ROM "a Werewolf Tale".

Part of #12739

testing/mgba/APKBUILD

@@ -3,14 +3,14 @@
 # Maintainer:
 pkgname=mgba
 pkgver=0.9.2
-pkgrel=0
+pkgrel=1
 pkgdesc="Game Boy Advance Emulator"
 url="https://mgba.io"
 arch="all !s390x !mips !mips64" # broken on big-endian
 arch="$arch !armhf" # Missing qt5-qtmultimedia-dev
 license="MPL-2.0"
 makedepends="cmake qt5-qtmultimedia-dev qt5-qtbase-dev qt5-qttools-dev
-	sdl-dev libzip-dev zlib-dev libpng-dev ffmpeg-dev imagemagick-dev
+	sdl2-dev libzip-dev zlib-dev libpng-dev ffmpeg-dev imagemagick-dev
 	libepoxy-dev cmocka-dev libedit-dev py3-virtualenv python3-dev
 	libzip-tools elfutils-dev
 	"