meson: simplify dependencies

Leverage wrapfile `[provide]` directives to simplify the dependency
searching in the meson.build.

Change-Id: I3ffeb36c566eed00a6070b6c823d9a7b2a8bfbc2
diff --git a/subprojects/phosphor-logging.wrap b/subprojects/phosphor-logging.wrap
index a039fcf..71eee8b 100644
--- a/subprojects/phosphor-logging.wrap
+++ b/subprojects/phosphor-logging.wrap
@@ -1,3 +1,6 @@
 [wrap-git]
 url = https://github.com/openbmc/phosphor-logging.git
 revision = HEAD
+
+[provide]
+phosphor-logging = phosphor_logging_dep