Fix Docker image build

Commit a40fd0b adds objects file that built with the lib of SDL2 and
SDL2_mixer for linker when building rv_histogram, the current Docker
image lacks of SDL2 and SDL2_mixer shared objects, so installing them
to fix the missing shared objects.

The final Docker image size changes from around 4 MiB -> 28 MiB.

Author: ChinYikMing

Dockerfile

@@ -1,21 +1,23 @@
 FROM alpine:3.19 AS base_gcc
 
-RUN apk add --update alpine-sdk git wget
+RUN apk add --update alpine-sdk git wget sdl2-dev sdl2_mixer-dev
 
 # copy in the source code
 WORKDIR /home/root/rv32emu
 COPY . .
 
 # generate execution file for rv32emu and rv_histogram
-RUN make ENABLE_SDL=0
+RUN make
 RUN make tool
 
 FROM alpine:3.19 AS final
 
 # copy in elf files
 COPY ./build/*.elf /home/root/rv32emu/build/
 
-# get rv32emu and rv_histogram binaries
+# get rv32emu and rv_histogram binaries and lib of SDL2 and SDL2_mixer
+COPY --from=base_gcc /usr/include/SDL2/ /usr/include/SDL2/
+COPY --from=base_gcc /usr/lib/libSDL2* /usr/lib/
 COPY --from=base_gcc /home/root/rv32emu/build/rv32emu /home/root/rv32emu/build/rv32emu
 COPY --from=base_gcc /home/root/rv32emu/build/rv_histogram /home/root/rv32emu/build/rv_histogram