staging: vt6656: MACvSetKeyEntry create structure to write key

Create structure for wKeyCtl , pbyAddr and pbyKey

wKeyCtl(key_ctl) and pbyAddr(addr) form an union of 64 bits with swap
of two 32 bits. pbyKey(key) has a length of WLAN_KEY_LEN_CCMP(16)
bytes.

swap is needed because high order 32 bits needs to written out first.

pbyKey is memcpy on to key.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>