package/ltp-testsuite: introduce BR2_PACKAGE_LTP_TESTSUITE_ARCH_SUPPORTS
ltp-testsuite needs __sync*() built-ins for 4-byte data, except on a few
architectures for which a specific implementation is provided in
ltp-testsuite source code.
To prepare for the introduction of this dependency, add
BR2_PACKAGE_LTP_TESTSUITE_ARCH_SUPPORTS.
Signed-off-by: Romain Naour <romain.naour@gmail.com>
[Thomas: slightly adjust how the ARCH_SUPPORTS option is defined.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>