fix(optee): add sysroot flags to toolchain setup

Current toolchain setup steps are missing sysroot flags required by
OP-TEE and U-Boot build systems, causing "cannot find libgcc.a" linker
errors.

Add CFLAGS64, KCFLAGS, and LDFLAGS exports with sysroot for 64-bit
builds. Add SYSROOT_32 and CFLAGS32 for 32-bit builds.

Signed-off-by: Shiva Tripathi <[email protected]>

Author: shiva-ti

source/linux/Overview/GCC_ToolChain.rst

@@ -23,7 +23,17 @@ Before compiling any of the sources referenced in this document, set the cross c
       host# export CROSS_COMPILE_64="${SDK_INSTALL_DIR}/linux-devkit/sysroots/x86_64-arago-linux/usr/bin/aarch64-oe-linux/aarch64-oe-linux-"
       host# export SYSROOT_64="${SDK_INSTALL_DIR}/linux-devkit/sysroots/aarch64-oe-linux"
       host# export CC_64="${CROSS_COMPILE_64}gcc --sysroot=${SYSROOT_64}"
+      host# export CFLAGS64="--sysroot=${SYSROOT_64}"
+      host# export KCFLAGS="--sysroot=${SYSROOT_64}"
+      host# export LDFLAGS="--sysroot=${SYSROOT_64}"
+
+.. ifconfig:: CONFIG_part_variant not in ('AM335X', 'AM437X', 'AM57X', 'AM62LX')
+
+   .. code-block:: console
+
       host# export CROSS_COMPILE_32="${SDK_INSTALL_DIR}/k3r5-devkit/sysroots/x86_64-arago-linux/usr/bin/arm-oe-eabi/arm-oe-eabi-"
+      host# export SYSROOT_32="${SDK_INSTALL_DIR}/k3r5-devkit/sysroots/armv7at2hf-vfp-oe-eabi"
+      host# export CFLAGS32="--sysroot=${SYSROOT_32}"
 
 If the Processor SDK is not installed, the Arm GNU toolchains can be downloaded and setup. Refer to :ref:`external-arm-toolchain` section for more details on usage.