libsdl2-compat: add runtime dependency on libsdl3

libSDL2-2.0.so.0 from sdl2-compat lists only libc.so.6 as NEEDED and
loads libSDL3.so.0 through dlopen(), so shlibs does not generate a
runtime dependency on libsdl3. An image that installs an SDL2 consumer
without pulling in libsdl3 by other means therefore gets a library that
fails to initialize at runtime. This was seen with plasma-desktop, whose
game controller KCM links against SDL2 and made systemsettings fail to
start on an image that had no other SDL user.

Tested by checking readelf -d on the installed libSDL2-2.0.so.0 and by
rebuilding the package for corei7-64.

AI-Generated: Uses Claude Code (Claude Opus 5)
Signed-off-by: Markus Volk <f_l_k@t-online.de>
Signed-off-by: Khem Raj <khem.raj@oss.qualcomm.com>

meta-oe/recipes-graphics/libsdl3/libsdl2-compat_2.32.70.bb

@@ -31,6 +31,8 @@ do_install:append() {
 
 FILES:${PN} += "${datadir}/licenses"
 
+RDEPENDS:${PN} += "libsdl3"
+
 RCONFLICTS:${PN} = "libsdl2"
 RPROVIDES:${PN} = "libsdl2"