iwlwifi: testmode new indirect RW API

Replaced the old SRAM and periphery indirect access functions
with a unified indirect memory access functions. These include
new IWL_TM_CMDs for buffer read/write/dump which replace the
SRAM read/dump commands, but the API for IWL_TM_CMD_INDIRECT_REG
read/write will now not be supported (returns error).

This also handles writing to periphery registers in 1-3 bytes.

Requires the corresponding patch in the library for the API change.

Signed-off-by: Amit Beka <amit.beka@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>