wifi: rtw89: phy: add PHY context array to support functions per PHY

wifi: rtw89: phy: add PHY context array to support functions per PHY

To support MLO working on PHY 0 and PHY 1, extend existing PHY dynamic
mechanism from PHY 0 to PHY 0/1.

Implement a 2 elements array for two PHY instances, and pass pointer
of each element as argument to existing functions. Then existing algorithm
is kept, unchanged.

Also provide iterate and get function to access PHY context.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20250117072828.16728-3-pkshih@realtek.com