libpldm: Add APIs to enable PLDM Requester flow

Implement requester APIs outlined at
https://github.com/openbmc/docs/blob/master/designs/pldm-stack.md#Requester.

Sync (send request msg and wait for response) and async (send request
msg and have caller poll an fd) APIs have been implemented. Example apps
that use both flavor of APIs have been implemented as well.

These APIs depend on openbmc/libmctp. For that reason and given the
OpenBMC agnostic nature of libpldm, these APIs must be conditionally
built via a meson feature (requester-api).

Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
Change-Id: I666a534d8c876638a29074d62c2ed700f33229a8
diff --git a/meson_options.txt b/meson_options.txt
index 97e6580..1c059db 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -1,3 +1,5 @@
 option('tests', type: 'feature', description: 'Build tests', value: 'enabled')
 option('oe-sdk', type: 'feature', description: 'Enable OE SDK')
 option('oem-ibm', type: 'feature', description: 'Enable IBM OEM PLDM', value: 'enabled')
+option('requester-api', type: 'feature', description: 'Enable libpldm requester API', value: 'enabled')
+option('utilities', type: 'feature', description: 'Enable debug utilities', value: 'enabled')