pycryptodomex: cleanup recipe to use common include

PyCryptodome is "an almost drop-in replacement for the old PyCrypto library"
and installs under "Crypto" package. In cases when both PyCryptodome and old
PyCrypto are needed, there's PyCryptodomeX that installs under own name as
"Cryptodome" package.

Signed-off-by: Denys Dmytriyenko <denys@ti.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-python/recipes-devtools/python/python-pycryptodome.inc

@@ -21,7 +21,7 @@ RDEPENDS_${PN}-tests += " \
 
 PACKAGES =+ "${PN}-tests"
 
-FILES_${PN}-tests += " \
+FILES_${PN}-tests = " \
     ${PYTHON_SITEPACKAGES_DIR}/Crypto/SelfTest/ \
     ${PYTHON_SITEPACKAGES_DIR}/Crypto/SelfTest/__pycache__/ \
 "