SDL: psp: Fixed building with pspdev when not using CMake.

SDL Commits
1 
From 0d007bbb014311542f28dd83704a649ce4eaed75 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Thu, 28 Mar 2024 09:27:21 -0400
Subject: [PATCH] psp: Fixed building with pspdev when not using CMake.

(psp-cmake defines `__PSP__` on the command line, but the compiler itself
only defines `__psp__` and some variations.

Fixes #9378.
---
 include/SDL3/SDL_platform_defines.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/SDL3/SDL_platform_defines.h b/include/SDL3/SDL_platform_defines.h
index 8083619d89a1c..de0908f4597b7 100644
--- a/include/SDL3/SDL_platform_defines.h
+++ b/include/SDL3/SDL_platform_defines.h
@@ -183,7 +183,7 @@
 #if defined(SDL_PLATFORM_WINGDK) || defined(SDL_PLATFORM_XBOXONE) || defined(SDL_PLATFORM_XBOXSERIES)
 #define SDL_PLATFORM_GDK    1
 #endif
-#ifdef __PSP__
+#if defined(__PSP__) || defined(__psp__)
 #define SDL_PLATFORM_PSP    1
 #endif
 #if defined(__PS2__) || defined(PS2)