binder: remove Rust implementation

This is part of the effort to minimize the differences of the `rust`
branch with respect to mainline in order to eventually drop it.

Since the Rust Binder development is now done elsewhere as a
downstream project of Rust for Linux, remove it from here.

Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Matt Gilbride <mattgilbride@google.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: ojeda

.github/workflows/ci.yaml

@@ -375,15 +375,13 @@ jobs:
           ls -l \
             ${{ env.BUILD_DIR }}samples/rust/*.o \
             ${{ env.BUILD_DIR }}samples/rust/*.ko \
-            ${{ env.BUILD_DIR }}drivers/android/rust_binder.o \
             ${{ env.BUILD_DIR }}rust/*.o \
             ${{ env.BUILD_DIR }}vmlinux \
             ${{ env.BUILD_DIR }}${{ env.IMAGE_PATH }}
 
           .github/workflows/size.sh \
             ${{ env.BUILD_DIR }}samples/rust/*.o \
             ${{ env.BUILD_DIR }}samples/rust/*.ko \
-            ${{ env.BUILD_DIR }}drivers/android/rust_binder.o \
             ${{ env.BUILD_DIR }}rust/*.o \
             ${{ env.BUILD_DIR }}vmlinux
 

drivers/android/Kconfig

@@ -13,12 +13,6 @@ config ANDROID_BINDER_IPC
 	  Android process, using Binder to identify, invoke and pass arguments
 	  between said processes.
 
-config ANDROID_BINDER_IPC_RUST
-	bool "Android Binder IPC Driver in Rust"
-	depends on MMU && RUST
-	help
-	  Implementation of the Binder IPC in Rust.
-
 config ANDROID_BINDERFS
 	bool "Android Binderfs filesystem"
 	depends on ANDROID_BINDER_IPC

drivers/android/Makefile

@@ -4,5 +4,3 @@ ccflags-y += -I$(src)			# needed for trace events
 obj-$(CONFIG_ANDROID_BINDERFS)		+= binderfs.o
 obj-$(CONFIG_ANDROID_BINDER_IPC)	+= binder.o binder_alloc.o
 obj-$(CONFIG_ANDROID_BINDER_IPC_SELFTEST) += binder_alloc_selftest.o
-
-obj-$(CONFIG_ANDROID_BINDER_IPC_RUST) += rust_binder.o