license: Rename the directory

Rename the directory to "licenses" to avoid
name conflicts on the case-insensitive file system
like Windows and MacOS

Signed-off-by: Alexey Marchuk <alexeymar@nvidia.com>
Change-Id: I090d7d026c8669517876bdee38d486589645d5b1
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/13551


Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>