package/sdl2_image: bump version to 2.8.4

For release notes since 2.8.2, see:
https://github.com/libsdl-org/SDL_image/releases/tag/release-2.8.3
https://github.com/libsdl-org/SDL_image/releases/tag/release-2.8.4

Signed-off-by: Peter Macleod Thompson <peter.macleod.thompson@gmail.com>
[Julien: add links to release notes]
Signed-off-by: Julien Olivain <ju.o@free.fr>

package/sdl2_image/sdl2_image.hash

@@ -1,3 +1,3 @@
 # Locally calculated
-sha256  8f486bbfbcf8464dd58c9e5d93394ab0255ce68b51c5a966a918244820a76ddc  SDL2_image-2.8.2.tar.gz
+sha256  f7c06a8783952cfe960adccdd3d8472b63ab31475b4390d10cfdcc1aea61238f  SDL2_image-2.8.4.tar.gz
 sha256  a0e8ce06504966e45088ee1cc7583cc8af9aac615d4cf56d47d847da9cb15139  LICENSE.txt

package/sdl2_image/sdl2_image.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-SDL2_IMAGE_VERSION = 2.8.2
+SDL2_IMAGE_VERSION = 2.8.4
 SDL2_IMAGE_SOURCE = SDL2_image-$(SDL2_IMAGE_VERSION).tar.gz
 SDL2_IMAGE_SITE = http://www.libsdl.org/projects/SDL_image/release
 SDL2_IMAGE_INSTALL_STAGING = YES