Cross-referencing to "fake" sub-pictures

I suppose you could insert a dummy subfigure environment, containing no graphs but just four \refstepcounter and \label directives, inside the figure environment to create four implicit (but invisible) subfigures.

That said, I can see nothing wrong in just writing "As shown in Panels A and B of \cref{fig:model}, ..."

\documentclass[notitlepage, 12pt, demo]{report} % omit 'demo' option in real document
\usepackage{graphicx,subcaption}
\renewcommand\thesubfigure{\Alph{subfigure}} % OP wants uppercase letters

\usepackage[colorlinks,allcolors=blue]{hyperref} 
\usepackage[noabbrev,nameinlink]{cleveref}
\crefformat{figure}{#2(\figurename~#1)#3}
 
\begin{document}

\begin{figure}[h]
\begin{subfigure}{1\textwidth} % this 'subfigure' env. has no visible content
    \refstepcounter{subfigure}\label{fig:model:a}
    \refstepcounter{subfigure}\label{fig:model:b}
    \refstepcounter{subfigure}\label{fig:model:c}
    \refstepcounter{subfigure}\label{fig:model:d}
\end{subfigure}%
\includegraphics[width=\textwidth]{imagens/model.png}
\caption{A figure with four implicit subfigures}
\label{fig:model}
\end{figure}

As shown in \cref{fig:model:a} and \cref{fig:model:b}, \dots

As shown in Panels A and B of \cref{fig:model}, \dots
\end{document}

This draws on Mico's answer, but also sets the anchors (approximately) at the right points: if you click on the links, you get moved to the proper subfigure.

The idea is to produce four empty subfigure environments that take the same space as the subfigures (the “approximate” refers to the small gap between the images, but it should not be a big concern). After these empty environments, the image is printed, but taking no vertical space, so it will exactly cover the previous space.

\documentclass{article}
\usepackage{graphicx,subcaption}
\usepackage{hyperref} 
\usepackage{cleveref}

\crefformat{figure}{#2(\figurename~#1)#3}
\newsavebox{\fourfigurebox}

\begin{document}

\cref{four:a},
\cref{four:b},
\cref{four:c},
\cref{four:d},
\cref{four}.

\begin{figure}[htp]
\sbox\fourfigurebox{\includegraphics[width=\textwidth]{fourimages}}% change with your own image

\begin{subfigure}[t][0.5\ht\fourfigurebox]{0.5\textwidth}
\refstepcounter{subfigure}\label{four:a}
\end{subfigure}%<---- Don't forget
\begin{subfigure}[t][0.5\ht\fourfigurebox]{0.5\textwidth}
\refstepcounter{subfigure}\label{four:b}
\end{subfigure}\par\nointerlineskip
\begin{subfigure}[t][0.5\ht\fourfigurebox]{0.5\textwidth}
\refstepcounter{subfigure}\label{four:c}
\end{subfigure}%<---- Don't forget
\begin{subfigure}[t][0.5\ht\fourfigurebox]{0.5\textwidth}
\refstepcounter{subfigure}\label{four:d}
\end{subfigure}\par\nointerlineskip
\smash{\usebox{\fourfigurebox}}

\caption{These are four images}\label{four}

\end{figure}

\end{document}