[EC] Unify scalar_mul_public for ec_nistp curves #4674

Job	Run time
haproxy	3m 26s
tpm2-tss	3m 39s
bind9	5m 10s
Cyrus-SASL	1m 55s
grpc	29m 47s
nmap	2m 32s
OpenLDAP	17m 16s
ntp	2m 23s
openvpn2-6	4m 19s
openvpnMaster	4m 5s
Python main	3m 58s
Python releases (FIPS=0 OPENSSL_IN_CRT=0)	12m 32s
Python releases (FIPS=1 OPENSSL_IN_CRT=0)	12m 20s
socat	5m 45s
strongswan	2m 12s
tcpdump	1m 23s
Python releases (FIPS=0 OPENSSL_IN_CRT=1)	11m 57s
Python releases (FIPS=1 OPENSSL_IN_CRT=1)	12m 49s
trousers	1m 21s
amazon-corretto-crypto-provider	21m 46s
libevent	29m 15s
	3h 9m 50s

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