gfx/vita2d: fold the vita2d GXM backend into the driver

vita2d_gfx.c was the only consumer of the vendored libvita2d, and it went
through the library's public API as if it were an external dependency,
unlike the gx (libogc) and rsx (PSL1GHT) console drivers which talk to
their GPU SDK directly. Fold the backend in so the Vita driver is a
self-contained GXM implementation like its siblings.

The four (already dead-code-stripped) translation units -- vita2d.c,
vita2d_texture.c, vita2d_draw.c, utils.c -- and their headers are inlined
into vita2d_gfx.c; the driver no longer includes <vita2d.h> and the public
vita2d API is gone. The precompiled shader blobs (shader/*.gxp.c) stay --
the folded code still references them as externs.

  - deps/libvita2d/{source,include}/* and the standalone Makefile deleted;
    LICENSE and the shader/ blobs retained.
  - Makefile.common: drop the four source objects, keep the eight shader
    objects, drop the now-unused -Ideps/libvita2d/include.
  - griffin.c / Makefile.griffin: drop the source #includes and include dir.

Compile-verified with vitasdk (arm-vita-eabi-gcc 15.2.0, -march=armv7-a
-mfpu=neon -mfloat-abi=hard): builds to a clean object, no errors.

Signed-off-by: LibretroAdmin <LibretroAdmin@users.noreply.github.com>

Author: LibretroAdmin

Makefile.common

@@ -1219,11 +1219,9 @@ ifeq ($(HAVE_THREAD_STORAGE), 1)
 endif
 
 ifeq ($(HAVE_VITA2D), 1)
-   OBJ += $(DEPS_DIR)/libvita2d/source/vita2d.o \
-          $(DEPS_DIR)/libvita2d/source/vita2d_texture.o \
-          $(DEPS_DIR)/libvita2d/source/vita2d_draw.o \
-          $(DEPS_DIR)/libvita2d/source/utils.o
-
+   # The vita2d GXM backend is now folded directly into vita2d_gfx.c; only
+   # the precompiled shader blobs remain as a dependency (the driver still
+   # references clear_v_gxp/texture_v_gxp/... as externs).
    OBJ += $(DEPS_DIR)/libvita2d/shader/clear_v_gxp.o \
           $(DEPS_DIR)/libvita2d/shader/clear_f_gxp.o \
           $(DEPS_DIR)/libvita2d/shader/color_v_gxp.o \
@@ -1234,8 +1232,6 @@ ifeq ($(HAVE_VITA2D), 1)
           $(DEPS_DIR)/libvita2d/shader/texture_tint_f_gxp.o
 
    OBJ += gfx/drivers/vita2d_gfx.o
-
-   INCLUDE_DIRS += -I$(DEPS_DIR)/libvita2d/include
 endif
 
 ifeq ($(TARGET), retroarch_3ds)

Makefile.griffin

@@ -315,7 +315,6 @@ else ifeq ($(platform), vita)
    EXT_TARGET := $(TARGET_NAME)_$(platform).velf
    EXT_INTER_TARGET := $(TARGET_NAME)_$(platform).elf
    MACHDEP := -DVITA
-   INCLUDE += -Ideps/libvita2d/include
    PLATCFLAGS := -mfloat-abi=hard -fsingle-precision-constant \
         -mword-relocations -fno-unwind-tables -fno-asynchronous-unwind-tables -ftree-vectorize -fno-optimize-sibling-calls
    LIBS += -lSceDisplay_stub -lSceGxm_stub -lSceNet_stub -lSceNetCtl_stub\