staging: wilc1000: delete wilc_memory.c and wilc_memory.h

The macro WILC_MALLOC is not used in the driver anymore, so just
delete files.

Signed-off-by: Glen Lee <glen.lee@atmel.com>
Signed-off-by: Tony Cho <tony.cho@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>