uboot-imx

net: zynq: Allocate BD_SPACE in connection to RX_BUF

BD_SEPRN_SPACE should not have hard coded value and it will be
calculated based on the number of buffer descriptors that we
would like to use.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>