SoC common : build: Unable to correctly locate the RISC-V toolchain. [1/1]

PD#SWPL-69248

Problem:
Unable to correctly locate the toolchain during backtrace extension compilation.

Solution:
Export new environment variables

Verify:
N/A

Change-Id: Ic7fa22f0629456ad6c3ca544ffd0d42775090a3e
Signed-off-by: shijie.xiong <shijie.xiong@amlogic.com>
diff --git a/symtable.mk b/symtable.mk
index f714fb1..662e955 100644
--- a/symtable.mk
+++ b/symtable.mk
@@ -1,8 +1,5 @@
-B_PRJDIR := $(SDK_BASE)
-kernel_B_BUILD_DIR := $(kernel_BUILD_DIR)
-
 NM:=$(TOOLCHAIN_KEYWORD)-nm
-CC:=$(TOOLCHAIN_KEYWORD)-$(COMPILER)
+PATH:=$(TOOLCHAIN_PATH)/bin:$(PATH)
 
 quiet=silent_
 cmd = $(if $($(quiet)cmd_$(1)),echo '  $($(quiet)cmd_$(1))' &&) $(cmd_$(1))
@@ -12,14 +9,14 @@
 		LC_ALL=C sort | sed 's/0000000000//'
 
 cmd_smap ?= \
-	smap_addr=`$(call SYSTEM_MAP,${kernel_B_BUILD_DIR}/freertos.elf) | \
+	smap_addr=`$(call SYSTEM_MAP,${kernel_BUILD_DIR}/freertos.elf) | \
 		awk '$$2 ~ /[tTwW]/ {printf $$1 " "}'` ; \
-	smap_sym=`$(call SYSTEM_MAP,${kernel_B_BUILD_DIR}/freertos.elf) | \
+	smap_sym=`$(call SYSTEM_MAP,${kernel_BUILD_DIR}/freertos.elf) | \
 		awk '$$2 ~ /[tTwW]/ {printf $$3 " "}'` ; \
-	echo "char const system_map_addr[] = {" > $(B_PRJDIR)/lib/backtrace/system_map_addr.c;\
-	echo "\"$${smap_addr}\"\"\\\\000\"};" >> $(B_PRJDIR)/lib/backtrace/system_map_addr.c;\
-	echo "char const system_map_sym[] = {" > $(B_PRJDIR)/lib/backtrace/system_map_sym.c;\
-	echo "\"$${smap_sym}\"\"\\\\000\"};" >> $(B_PRJDIR)/lib/backtrace/system_map_sym.c;
+	echo "char const system_map_addr[] = {" > $(SDK_BASE)/lib/backtrace/system_map_addr.c;\
+	echo "\"$${smap_addr}\"\"\\\\000\"};" >> $(SDK_BASE)/lib/backtrace/system_map_addr.c;\
+	echo "char const system_map_sym[] = {" > $(SDK_BASE)/lib/backtrace/system_map_sym.c;\
+	echo "\"$${smap_sym}\"\"\\\\000\"};" >> $(SDK_BASE)/lib/backtrace/system_map_sym.c;
 
 .PHONY: backtrace
 backtrace:
@@ -27,7 +24,7 @@
 
 .PHONY: clean
 clean:
-	@truncate -s 0 $(B_PRJDIR)/lib/backtrace/system_map_addr.c
-	@truncate -s 0 $(B_PRJDIR)/lib/backtrace/system_map_sym.c
-	@echo "char const system_map_addr[] = {0};" > $(B_PRJDIR)/lib/backtrace/system_map_addr.c
-	@echo "char const system_map_sym[] = {0};" > $(B_PRJDIR)/lib/backtrace/system_map_sym.c
+	@truncate -s 0 $(SDK_BASE)/lib/backtrace/system_map_addr.c
+	@truncate -s 0 $(SDK_BASE)/lib/backtrace/system_map_sym.c
+	@echo "char const system_map_addr[] = {0};" > $(SDK_BASE)/lib/backtrace/system_map_addr.c
+	@echo "char const system_map_sym[] = {0};" > $(SDK_BASE)/lib/backtrace/system_map_sym.c