When building tx command, always set TX_CMD_FLAG_PROT_REQUIRE_MSK
for 5000 series and up.

Without setting this bit the firmware will not examine the RTS/CTS setting
and thus not send traffic with the appropriate protection. RTS/CTS is is
required for HT traffic in a noisy environment where, without this setting,
connections will stall on some hardware as documented in the patch that
initially attempted to address this:

    commit 1152dcc2
    Author: Wey-Yi Guy <wey-yi.w.guy@intel.com>
    Date:   Fri Jan 15 13:42:58 2010 -0800

    iwlwifi: Fix throughput stall issue in HT mode for 5000

    Similar to 6000 and 1000 series, RTS/CTS is the recommended
    protection mechanism for 5000 series in HT mode based on the HW design.
    Using RTS/CTS will better protect the inner exchange from interference,
    especially in highly-congested environment, it also prevent uCode encounter
    TX FIFO underrun and other HT mode related performance issues.

For 3945 and 4965, different flags are used for RTS/CTS or CTS-to-Self
protection.
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

Some future hardware will require a different command to
be sent for bluetooth coexist, so make this a virtual
method that can be changed on a per-device basis.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

Scan requesting doesn't need to be asynchronous
since all code paths leading up to it can sleep.
Make the scan request a new util operation that
is hw-specific (to account for 3945 vs. agn)
and call it right in place.

This patch moves a lot of code into iwlagn as
it need not be in iwlcore.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

Some defines used by all agn devices, but the definitions were in
iwl-4965-hw.h, move those to iwl-agn-hw.h which is the better place for
those.
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

After re-structure the agn files layout and move all the
agn shared functions out from iwl-5000.c, all those functions and data
structures do not need to be declare "extern" from iwl-5000.c in
iwl-dev.h.
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

Multiple iwlagn based devices shared the same hw definitions.
Move device hardware related defines from iwl-5000-hw.h to iwl-agn-hw.h
file.
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>

Multiple iwlagn based devices shared the same hcmd related functions.
Move from iwl-5000.c to iwl-agn-hcmd.c file.
Signed-off-by: NWey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>