iwlwifi: yoyo: fix issue with new DBGI_SRAM region read.

NIC has been grabbed for reading twice which is leading
to NIC hang. Code correction are done for reading data with
no grab function.

Signed-off-by: Mukesh Sisodiya <mukesh.sisodiya@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211219132536.55527214f8c9.I1748215ccb3fa20a3491a46a49b12e04eb560ac6@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>