As the plain neon qpel_h functions process two rows at a time,
we need to allocate storage for h+8 rows instead of h+7.
AWS Graviton 3:
put_hevc_qpel_uni_w_hv4_8_c: 422.2
put_hevc_qpel_uni_w_hv4_8_neon: 140.7
put_hevc_qpel_uni_w_hv4_8_i8mm: 100.7
put_hevc_qpel_uni_w_hv8_8_c: 1208.0
put_hevc_qpel_uni_w_hv8_8_neon: 268.2
put_hevc_qpel_uni_w_hv8_8_i8mm: 261.5
put_hevc_qpel_uni_w_hv16_8_c: 4297.2
put_hevc_qpel_uni_w_hv16_8_neon: 802.2
put_hevc_qpel_uni_w_hv16_8_i8mm: 731.2
put_hevc_qpel_uni_w_hv32_8_c: 15518.5
put_hevc_qpel_uni_w_hv32_8_neon: 3085.2
put_hevc_qpel_uni_w_hv32_8_i8mm: 2783.2
put_hevc_qpel_uni_w_hv64_8_c: 57254.5
put_hevc_qpel_uni_w_hv64_8_neon: 11787.5
put_hevc_qpel_uni_w_hv64_8_i8mm: 10659.0
Signed-off-by: Martin Storsjö <martin@martin.st>