iwlwifi: mvm: remove the read_nvm from iwl_run_init_mvm_ucode

If we already read the NVM, we don't need to read it again.
Make sure that this is the case with a WARNING.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20201209231352.8e0ffce7f873.Ie526042c4d4b93d9116c90f53180cbadef0b32cb@changeid


Signed-off-by: Luca Coelho <luciano.coelho@intel.com>