net/bnxt: refactor flow id allocation

net/bnxt: refactor flow id allocation

Currently, the flow id is allocated inside ulp_mapper_flow_create.
However with vxlan decap feature if F2 flow comes before F1 flow
then F2 is cached and not really installed in the hardware which
means the code will return without calling ulp_mapper_flow_create.
But, ULP has to still return valid flow id to the stack.
Hence, move the flow id allocation outside ulp_mapper_flow_create.

Signed-off-by: Venkat Duvvuru <venkatkumar.duvvuru@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>