fix(demos): fix demos compiling error caused by font config (#4778)

Signed-off-by: YanXiaowei <yanxiaowei@xiaomi.com>
Co-authored-by: YanXiaowei <yanxiaowei@xiaomi.com>

Kconfig

@@ -1387,6 +1387,7 @@ menu "LVGL configuration"
 		config LV_USE_DEMO_BENCHMARK
 			bool "Benchmark your system"
 			default n
+			depends on LV_FONT_MONTSERRAT_14 && LV_FONT_MONTSERRAT_24
 		config LV_DEMO_BENCHMARK_RGB565A8
 			bool "Use RGB565A8 images with 16 bit color depth instead of ARGB8565"
 			depends on LV_USE_DEMO_BENCHMARK
@@ -1396,6 +1397,11 @@ menu "LVGL configuration"
 			bool "Stress test for LVGL"
 			default n
 
+		config LV_USE_DEMO_TRANSFORM
+			bool "Transform test for LVGL"
+			default n
+			depends on LV_FONT_MONTSERRAT_18
+
 		config LV_USE_DEMO_MUSIC
 			bool "Music player demo"
 			default n

demos/benchmark/lv_demo_benchmark.c

@@ -9,6 +9,15 @@
 #include "lv_demo_benchmark.h"
 
 #if LV_USE_DEMO_BENCHMARK
+
+#if LV_FONT_MONTSERRAT_14 == 0
+    #error "LV_FONT_MONTSERRAT_14 is required for lv_demo_benchmark. Enable it in lv_conf.h."
+#endif
+
+#if LV_FONT_MONTSERRAT_24 == 0
+    #error "LV_FONT_MONTSERRAT_24 is required for lv_demo_benchmark. Enable it in lv_conf.h."
+#endif
+
 #include "../../src/display/lv_display_private.h"
 #include "../../src/core/lv_global.h"
 

demos/transform/lv_demo_transform.c

@@ -10,6 +10,10 @@
 
 #if LV_USE_DEMO_TRANSFORM
 
+#if LV_FONT_MONTSERRAT_18 == 0
+    #error "LV_FONT_MONTSERRAT_18 is required for lv_demo_transform. Enable it in lv_conf.h."
+#endif
+
 /*********************
  *      DEFINES
  *********************/