specs: fix the description for the [ug]idMappings
specs: fix the description for the [ug]idMappings

The fields in the [ug]idMappings are changed, we should fix
the description correspondingly.

Signed-off-by: Lai Jiangshan <b337eedf453972390e4695e362aeea2634ef4e0c@gmail.com>

zenlinTechnofreak/specs,cloudfoundry-incubator/specs,hqhq/specs,jonboulle/specs,marcosnils/specs,HardikDR/specs,wking/opencontainer-specs,vbatts/specs,ChengTiesheng/specs,laijs/specs,hqhq/runtime-spec,dustymabe/specs,wking/opencontainer-runtime-spec,philips/specs,LK4D4/specs,opencontainers/specs,kensipe/specs,gao-feng/specs,vishh/specs,mheon/specs,ujuc/specs,opencontainers/runtime-spec,navidshaikh/specs,talwai/specs,runcom/specs,wangkirin/specs