support/testing: test_rust: remove kernel build

This test already use builtin kernel provided by the testsuite infra:

    self.emulator.boot(arch="armv7",
                       kernel="builtin",
                       options=["-initrd", img])

But a second kernel is build from the its defconfig. This second kernel
is not used by the test.

The TestRust (using BR2_PACKAGE_HOST_RUST=y) is really long to build,
save some cpu time by removing the kernel build.

This unused kernel (based on 4.11.3 release) doesn't even build with
host gcc >= 10.

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
(cherry picked from commit f6d438d59fbb291e677edc030150944ee61feb4d)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

support/testing/tests/package/test_rust.py

@@ -65,12 +65,6 @@ class TestRustBin(TestRustBase):
         BR2_TOOLCHAIN_EXTERNAL=y
         BR2_TARGET_GENERIC_GETTY_PORT="ttyAMA0"
         BR2_SYSTEM_DHCP="eth0"
-        BR2_LINUX_KERNEL=y
-        BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-        BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.11.3"
-        BR2_LINUX_KERNEL_DEFCONFIG="vexpress"
-        BR2_LINUX_KERNEL_DTS_SUPPORT=y
-        BR2_LINUX_KERNEL_INTREE_DTS_NAME="vexpress-v2p-ca9"
         BR2_TARGET_ROOTFS_CPIO=y
         # BR2_TARGET_ROOTFS_TAR is not set
         BR2_PACKAGE_HOST_RUSTC=y
@@ -93,12 +87,6 @@ class TestRust(TestRustBase):
         BR2_TOOLCHAIN_EXTERNAL=y
         BR2_TARGET_GENERIC_GETTY_PORT="ttyAMA0"
         BR2_SYSTEM_DHCP="eth0"
-        BR2_LINUX_KERNEL=y
-        BR2_LINUX_KERNEL_CUSTOM_VERSION=y
-        BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="4.11.3"
-        BR2_LINUX_KERNEL_DEFCONFIG="vexpress"
-        BR2_LINUX_KERNEL_DTS_SUPPORT=y
-        BR2_LINUX_KERNEL_INTREE_DTS_NAME="vexpress-v2p-ca9"
         BR2_TARGET_ROOTFS_CPIO=y
         # BR2_TARGET_ROOTFS_TAR is not set
         BR2_PACKAGE_HOST_RUSTC=y