LU-12903 doc: make PCC man pages

LU-12903 doc: make PCC man pages

Several man pages for the Persistent Client Cache
feature were not included in the doc/Makefile.am
file and, thus, they do not show up on the Lustre client.

Add the following man pages to the Makefile:
lctl-pcc.8
lfs-pcc-detach.1
llapi_pcc_attach.3
llapi_pcc_attach_fid.3
llapi_pcc_attach_fid_str.3
llapi_pcc_detach_fid.3
llapi_pcc_detach_fid_fd.3
llapi_pcc_detach_fid_str.3
llapi_pcc_detach_file.3
llapi_pccdev_get.3
llapi_pccdev_set.3
llapi_pcc_state_get.3
llapi_pcc_state_get_fd.3

Test-Parameters: trivial
Fixes: f172b1168857 ("LU-10092 llite: Add persistent cache on client")
Signed-off-by: James Nunez <jnunez@whamcloud.com>
Change-Id: I4a7accb4ab77a9fcefda9f115a751ccbc35f9b7c
Reviewed-on: https://review.whamcloud.com/36572
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Joseph Gmitter <jgmitter@whamcloud.com>
Reviewed-by: Yingjin Qian <qian@ddn.com>