Update revisions

ibex c37edf50 [dv] Fix performance counter printing in simple system
e5dac438 Fix spelling of separator
508c4a29 [doc] Describe counters more explicitly in simple_system README
7647e9a0 Update lowrisc_ip to lowRISC/opentitan@e6a0e9a136
20cc063c [dv] Add an extra key to common_project_cfg.hjson

deps.json

@@ -1 +1 @@
-{"cores": [{"repository_name": "ibex", "repository_url": "https://github.com/lowRISC/ibex", "repository_branch": "master", "repository_revision": "fe84d64d794c0b1282c0e664d2eae6eeab22921a"}, {"repository_name": "Cores-VeeR-EL2", "repository_url": "https://github.com/chipsalliance/Cores-VeeR-EL2", "repository_branch": "main", "repository_revision": "97ffac34a3fd957a85f76daca6ac31443c4552a1"}, {"repository_name": "caliptra-rtl", "repository_url": "https://github.com/chipsalliance/caliptra-rtl", "repository_branch": "main", "repository_revision": "63ad025d1f796198386dd38aec5c17c12f5b24f6"}]}
+{"cores": [{"repository_name": "ibex", "repository_url": "https://github.com/lowRISC/ibex", "repository_branch": "master", "repository_revision": "c37edf50952bf60ef3650866b83a6b0c75b621ae"}, {"repository_name": "Cores-VeeR-EL2", "repository_url": "https://github.com/chipsalliance/Cores-VeeR-EL2", "repository_branch": "main", "repository_revision": "97ffac34a3fd957a85f76daca6ac31443c4552a1"}, {"repository_name": "caliptra-rtl", "repository_url": "https://github.com/chipsalliance/caliptra-rtl", "repository_branch": "main", "repository_revision": "63ad025d1f796198386dd38aec5c17c12f5b24f6"}]}