meson: Decouple 'oem-ibm' feature from parent projects

This was an artefact of libpldm's previous life where it was integrated
into OpenBMC's pldm.git.

Change-Id: I90f0004542a35d87b6653f49941ec5e2768d1da7
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
diff --git a/meson.options b/meson.options
index dcc1fdd..7f39b00 100644
--- a/meson.options
+++ b/meson.options
@@ -1,4 +1,4 @@
 option('abi', type: 'array', description: 'Constrain exposed symbol classes', choices: ['deprecated', 'stable', 'testing'], value: ['deprecated', 'stable', 'testing'])
 option('tests', type: 'feature', description: 'Build tests')
-option('oem-ibm', type: 'feature', description: 'Enable IBM OEM PLDM', yield: true)
+option('oem-ibm', type: 'feature', description: 'Enable IBM OEM PLDM')
 option('abi-compliance-check', type: 'feature', description: 'Detect public ABI/API changes')