Fix build system issues

This addresses the following critical build system issues:
1. Kconfig syntax error
   - Replace unsupported $(success,...) with Kconfiglib's $(shell,...)
   - Use 'def_bool $(shell,pkg-config --exists ... && echo y)' for
     dependency detection
2. Mixed target check logic
   - Change from "any goal matches" to "all goals match" logic
   - Use filter-out to verify all goals are known before including
     dependencies
   - Prevents build failures with mixed known/unknown targets
3. Multi-target invocation
   - Invert logic to only skip mk/common.mk for pure config/defconfig
   - Support mixed invocations like 'make defconfig all'
   - Handle empty goals (default to 'all')

Author: jserv

Makefile

@@ -177,10 +177,15 @@ endif
 
 CFLAGS += -include config.h
 
-# Only include build rules when not running configuration targets
-ifeq ($(filter $(check_goal),config defconfig),)
-include mk/common.mk
+# Only skip build rules when running ONLY config/defconfig (no other targets)
+ifneq ($(filter-out config defconfig,$(check_goal)),)
+    # Has targets other than config/defconfig
+    include mk/common.mk
+else ifeq ($(check_goal),)
+    # Empty goals means building 'all'
+    include mk/common.mk
 endif
+# Otherwise, only config/defconfig targets - skip mk/common.mk
 
 KCONFIGLIB := tools/kconfig/kconfiglib.py
 $(KCONFIGLIB):

configs/Kconfig

@@ -4,18 +4,18 @@ config CONFIGURED
     bool
     default y
 
-# Dependency detection using Kbuild toolchain functions
+# Dependency detection using Kconfiglib shell function
 config HAVE_SDL2
-    def_bool $(success,pkg-config --exists sdl2)
+    def_bool $(shell,pkg-config --exists sdl2 && echo y)
 
 config HAVE_PIXMAN
-    def_bool $(success,pkg-config --exists pixman-1)
+    def_bool $(shell,pkg-config --exists pixman-1 && echo y)
 
 config HAVE_LIBPNG
-    def_bool $(success,pkg-config --exists libpng)
+    def_bool $(shell,pkg-config --exists libpng && echo y)
 
 config HAVE_LIBJPEG
-    def_bool $(success,pkg-config --exists libjpeg)
+    def_bool $(shell,pkg-config --exists libjpeg && echo y)
 
 choice
     prompt "Backend Selection"

mk/common.mk

@@ -681,10 +681,11 @@ __FORCE:
 # Only include dependencies when building known targets
 build-goals := all clean $(target-builds)
 ifneq ($(MAKECMDGOALS),)
-    # MAKECMDGOALS is not empty, check if it's a known target
-    ifneq ($(filter $(MAKECMDGOALS),$(build-goals)),)
-        # Known target, include dependencies (except for clean)
-        ifneq "$(MAKECMDGOALS)" "clean"
+    # MAKECMDGOALS is not empty, check if ALL goals are known
+    # (i.e., no unknown goals remain after filtering out known ones)
+    ifeq ($(filter-out $(build-goals),$(MAKECMDGOALS)),)
+        # All goals are known, include dependencies (except for clean-only builds)
+        ifeq ($(filter clean,$(MAKECMDGOALS)),)
             -include $(target-depends)
         endif
     endif