meson: simplify dependencies

Leverage wrapfile `[provide]` directives to simplify the dependency
searching in the meson.build.  phosphor-dbus-interfaces now defaults to
enabling all of the project options, so there is no need to manually
specify this either.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I550667da15ce8347acfede53a60516a0428bad2b
diff --git a/extensions/openpower-pels/meson.build b/extensions/openpower-pels/meson.build
index bfa3889..7116668 100644
--- a/extensions/openpower-pels/meson.build
+++ b/extensions/openpower-pels/meson.build
@@ -1,6 +1,5 @@
 libpldm_dep = dependency(
     'libpldm',
-    fallback: ['pldm', 'libpldm_dep'],
     default_options: ['libpldm-only=enabled', 'oem-ibm=enabled'],
 )
 
@@ -23,10 +22,7 @@
 if cpp.has_header('CLI/CLI.hpp')
     CLI11_dep = declare_dependency()
 else
-    CLI11_dep = dependency(
-        'CLI11',
-        fallback: [ 'CLI11', 'CLI11_dep' ],
-    )
+    CLI11_dep = dependency('CLI11')
 endif
 
 extra_sources = []