EBBR.yaml: remove unused simple network protocol rule

This simple network protocol failure is not showing up anymore. Remove this
rule, as we want to reduce the list of WAIVED to zero.
Signed-off-by: Vincent Stehlé <vincent.stehle@arm.com>

EBBR.yaml

@@ -1589,25 +1589,6 @@
   update:
     result: WAIVED
 
-- rule: Force simple network protocol failures also failing with U-Boot
-    v2021.04-rc2 as waived
-  criteria:
-    descr: Simple Network Protocol Test
-    group: NetworkSupportTest
-    guid: 2143092E-03DD-4806-9FD6-08D42B9ABFC6
-    log: Status - Unsupported, Filter - 5500000000, Mask - 0,Count - 0(0),
-     Address - 0, 0, 0
-    name: EFI_SIMPLE_NETWORK_PROTOCOL.ReceiveFilters - Invoke ReceiveFilters()
-      to reset multicast receive filters list and verify interface correctness
-      within test case
-    result: FAILURE
-    revision: '0x00010001'
-    set guid: 7A1E587D-53AC-444E-A5A1-81CD3F4F04D4
-    sub set: ReceiveFilter_Func
-    test set: SimpleNetworkProtocolTest
-  update:
-    result: WAIVED
-
 - rule: Force misc runtime services failures also failing with U-Boot
     v2021.04-rc2 as waived
   criteria: