[bsp][bluetrum] remove .a file

bsp/bluetrum/ab32vg1-ab-prougen/board/Kconfig

 menu "Hardware Drivers Config"
 
+config SOC_AB32VG1
+    bool
+    select PKG_USING_BLUETRUM_SDK
+    default y
+
 menu "Onboard Peripheral Drivers"
 
     menuconfig BSP_USING_AUDIO

bsp/bluetrum/libraries/hal_libraries/ab32vg1_hal/SConscript

@@ -48,8 +48,8 @@ ASFLAGS          = ""
 CPPDEFINES       = []
 LOCAL_CPPDEFINES = []
 
-LIBS             = ['hal'] 
-LIBPATH          = [CWD]
+LIBS             = [] 
+LIBPATH          = []
 
 LINKFLAGS        = ""