Add riscv64 banchan target.

Test: banchan riscv64 com.android.art
Test: build/soong/build_test.bash --dist -products module_riscv64
Bug: 271573990
Change-Id: I6aa8c51b1a1928b3da52a9345a8bfb84e3eb11d0
diff --git a/envsetup.sh b/envsetup.sh
index d292dbb..f4755dd 100644
--- a/envsetup.sh
+++ b/envsetup.sh
@@ -62,8 +62,8 @@
               invocations of 'm' etc.
 - tapas:      tapas [<App1> <App2> ...] [arm|x86|arm64|x86_64] [eng|userdebug|user]
               Sets up the build environment for building unbundled apps (APKs).
-- banchan:    banchan <module1> [<module2> ...] [arm|x86|arm64|x86_64|arm64_only|x86_64only] \
-                      [eng|userdebug|user]
+- banchan:    banchan <module1> [<module2> ...] \
+                      [arm|x86|arm64|riscv64|x86_64|arm64_only|x86_64only] [eng|userdebug|user]
               Sets up the build environment for building unbundled modules (APEXes).
 - croot:      Changes directory to the top of the tree, or a subdirectory thereof.
 - m:          Makes from the top of the tree.
@@ -952,9 +952,9 @@
 function banchan()
 {
     local showHelp="$(echo $* | xargs -n 1 echo | \grep -E '^(help)$' | xargs)"
-    local product="$(echo $* | xargs -n 1 echo | \grep -E '^(.*_)?(arm|x86|arm64|x86_64|arm64only|x86_64only)$' | xargs)"
+    local product="$(echo $* | xargs -n 1 echo | \grep -E '^(.*_)?(arm|x86|arm64|riscv64|x86_64|arm64only|x86_64only)$' | xargs)"
     local variant="$(echo $* | xargs -n 1 echo | \grep -E '^(user|userdebug|eng)$' | xargs)"
-    local apps="$(echo $* | xargs -n 1 echo | \grep -E -v '^(user|userdebug|eng|(.*_)?(arm|x86|arm64|x86_64))$' | xargs)"
+    local apps="$(echo $* | xargs -n 1 echo | \grep -E -v '^(user|userdebug|eng|(.*_)?(arm|x86|arm64|riscv64|x86_64))$' | xargs)"
 
     if [ "$showHelp" != "" ]; then
       $(gettop)/build/make/banchanHelp.sh
@@ -980,6 +980,7 @@
       arm)    product=module_arm;;
       x86)    product=module_x86;;
       arm64)  product=module_arm64;;
+      riscv64) product=module_riscv64;;
       x86_64) product=module_x86_64;;
       arm64only)  product=module_arm64only;;
       x86_64only) product=module_x86_64only;;