The symlinks from hw2.1 to hw2.0 are already there by default:
/usr/lib/firmware/ath11k/WCN6855/hw2.0/:
total 1764
-rw-r--r-- 1 root root 12000 Nov 15 23:50 Notice.txt.xz
-rw-r--r-- 1 root root 1665096 Nov 15 23:50 amss.bin.xz
-rw-r--r-- 1 root root 15408 Nov 15 23:50 board-2.bin.xz
-rw-r--r-- 1 root root 105872 Nov 15 23:50 m3.bin.xz
-rw-r--r-- 1 root root 2132 Nov 15 23:50 regdb.bin.xz
/usr/lib/firmware/ath11k/WCN6855/hw2.1/:
total 0
lrwxrwxrwx 1 root root 20 Nov 15 23:50 amss.bin.xz -> ../hw2.0/amss.bin.xz
lrwxrwxrwx 1 root root 23 Nov 15 23:50 board-2.bin.xz -> ../hw2.0/board-2.bin.xz
lrwxrwxrwx 1 root root 18 Nov 15 23:50 m3.bin.xz -> ../hw2.0/m3.bin.xz
lrwxrwxrwx 1 root root 21 Nov 15 23:50 regdb.bin.xz -> ../hw2.0/regdb.bin.xz
Also the logs don’t really look like it is related to not finding the firmware, this shouldn’t lead to a 90s delay between these two lines:
[ 2.903757] mhi mhi0: Power on setup success
[ 95.397747] mhi mhi0: MHI did not load image over BHI, ret: -5