UPSTREAM: wifi: cfg80211: rename UHB to 6 GHz

UHB stands for "Ultra High Band", but this term doesn't really
exist in the spec. Rename all occurrences to "6 GHz", but keep
a few defines for userspace API compatibility.

Link: https://msgid.link/20240206164849.c9cfb9400839.I153db3b951934a1d84409c17fbe1f1d1782543fa@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Bug: 338806915
Change-Id: Ib7bbfce490a6b07f0fc6cca856e6459d88e0d3af
(cherry picked from commit 7b5e25b8)
Signed-off-by: Veerendranath Jakkam <quic_vjakkam@quicinc.com>