Fix minui issues for some build trees

In trees where TWRP is the primary recovery, minui.h was not setting rules
properly for healthd because healthd uses clang. Must use
CLANG_TARGET_GLOBAL_CFLAGS to set global flags.

Change-Id: I4cd9c88f8fcaec345fe012d09abcb9f24be06ef4
diff --git a/minui/minui.h b/minui/minui.h
index abef036..bf79601 100644
--- a/minui/minui.h
+++ b/minui/minui.h
@@ -55,7 +55,7 @@
 void gr_fill(int x1, int y1, int x2, int y2);
 
 void gr_texticon(int x, int y, GRSurface* icon);
-#ifndef TW_USE_MINUI_CUSTOM_FONTS
+#ifdef TW_NO_MINUI_CUSTOM_FONTS
 void gr_text(int x, int y, const char *s, bool bold);
 int gr_measure(const char *s);
 void gr_font_size(int *x, int *y);