test: Kconfig: Correct HAS_COVERAGE_SUPPORT description
test: Kconfig: Correct HAS_COVERAGE_SUPPORT description

HAS_COVERAGE_SUPPORT can be set both on boards with enough RAM to
store the coverage results, or for POSIX ARCH based ones

Signed-off-by: Alberto Escolar Piedras <52be3174920ed06cbdfbcf9622a1a6c68e942617@oticon.com>

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