databases/tiledb: Fix configure with CMake >= 3.27

After [1], CMake trusts OPENSSL_ROOT_DIR implicitly, so if isn't set
right, OpenSSL may not be found.

This project uses OPENSSL_PATHS to set OPENSSL_ROOT_DIR, so CMake tries
to find OpenSSL in TILEDB_EP_INSTALL_PREFIX which is problably not where
we want to look. Pass ${OPENSSLBASE} to set OPENSSL_PATHS so we are
looking in the right location.

[1] https://github.com/Kitware/CMake/commit/5cc8a69867ac42333a656607d90059a6db823abd

PR:		274225
Approved by:	portmgr (blanket build fix)