package/python-pycrypto: remove package

This package doesn't work with Python 3.8 since the code contains
time.clock() that was deprecated in Python 3.3 and removed in Python 3.8.

Instead of applying non upstream patches from Fedora [1], python-pycrypto
was replaced by python-pycryptodomex for crda and optee-os package.
Now we can remove safely this package.

[1] http://lists.busybox.net/pipermail/buildroot/2020-April/280683.html

Fixes:
https://gitlab.com/buildroot.org/buildroot/-/jobs/498144209



Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: James Hilliard <james.hilliard1@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>