arm64: ipred: Integrate aggregation into the first pass of cfl_ac
arm64: ipred: Integrate aggregation into the first pass of cfl_ac

Before:                Cortex A53     A72     A73
cfl_ac_420_w4_8bpc_neon:    131.8    75.6    70.8
cfl_ac_420_w8_8bpc_neon:    199.4   106.4   117.8
cfl_ac_420_w16_8bpc_neon:   370.6   194.6   213.3
cfl_ac_422_w4_8bpc_neon:     98.4    61.4    56.6
cfl_ac_422_w8_8bpc_neon:    237.7   134.2   141.0
cfl_ac_422_w16_8bpc_neon:   456.5   256.2   279.5
After:
cfl_ac_420_w4_8bpc_neon:    121.1    76.3    67.2
cfl_ac_420_w8_8bpc_neon:    188.7   106.6   115.3
cfl_ac_420_w16_8bpc_neon:   331.7   177.4   199.8
cfl_ac_422_w4_8bpc_neon:     88.7    57.3    51.6
cfl_ac_422_w8_8bpc_neon:    208.2   121.2   130.7
cfl_ac_422_w16_8bpc_neon:   393.8   226.3   239.3

videolan/dav1d