arm, arm64, xtensa, libxx: Change sed -r to sed -E to support macOS

[lupyuen]

Summary

When we build NuttX on macOS, it shows many sed messages (and the build still completes successfully):

$ tools/configure.sh pinephone:nsh
$ make
sed: illegal option -- r

(See the Complete Log)

This is due to the Makefiles executing sed -r which is not a valid option on macOS. (As explained here)

This PR proposes to change sed -r to sed -E because:

1. sed -E on macOS is equivalent to sed -r on Linux (See this)

2. sed -E and sed -r are aliases according to the GNU sed Manual

3. sed -E is already used in nuttx_add_romfs.cmake, nuttx_add_symtab.cmake and process_config.sh

Impact

On macOS: NuttX now builds without showing any sed messages.

On other platforms: There should be no impact, since sed -E and sed -r are functionally identical.

Testing

sed is used by the Makefiles to extract the GCC Major Version and the Clang Major / Minor Version. We tested the sed commands on Linux and macOS to verify that they work correctly:

## sed 4.9 on Linux 6.3.9 (Manjaro Arm64)
$ aarch64-none-elf-gcc --version
aarch64-none-elf-gcc (Arm GNU Toolchain 12.2.Rel1 (Build arm-12.24)) 12.2.1 20221205

$ aarch64-none-elf-gcc --version | grep gcc | sed -E "s/.* ([0-9]+\.[0-9]+).*/\1/" | cut -d'.' -f1
12

$ clang --version
clang version 15.0.7

$ clang --version | grep "clang version" | sed -E "s/.* ([0-9]+\.[0-9]+).*/\1/"
15.0

## sed on macOS 10.15.7
$ aarch64-none-elf-gcc --version
aarch64-none-elf-gcc (Arm GNU Toolchain 11.3.Rel1) 11.3.1 20220712

$ aarch64-none-elf-gcc --version | grep gcc | sed -E "s/.* ([0-9]+\.[0-9]+).*/\1/" | cut -d'.' -f1
11

$ clang --version
clang version 3.9.1 (tags/RELEASE_391/final)

$ clang --version | grep "clang version" | sed -E "s/.* ([0-9]+\.[0-9]+).*/\1/"
3.9

On macOS: NuttX now builds without showing any sed messages.