firmware: Modified TIInit_7.6.15.bts for WL1273(L)

"XTAL enable" paramter of "Send_HCI_VS_Fast_Clock_Configuration_btip" changed from 0x01 to 0xff

Signed-off-by: Victor Lin <vlin@ti.com>
Modifying TIInit_7.6.15.bts for WL127x(L) for AM335 platform