pcm-pp: revert r26756

FIQ/IRQ handlers can't be built with -mthumb, and the thumb case was
buggy anyway (spotted by jhMikeS) : pc offset hadn't been adjusted

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@26765 a1c6a512-1295-4272-9138-f99709370657

firmware/target/arm/pcm-pp.c

@@ -74,12 +74,7 @@ void fiq_handler(void) ICODE_ATTR __attribute__((naked));
 void fiq_handler(void)
 {
     asm volatile (
-#if ARM_ARCH == 4 && defined(USE_THUMB)
-        "ldr r12, [pc, #-4] \n"
-        "bx  r12            \n"
-#else
         "ldr pc, [pc, #-4]  \n"
-#endif
     "fiq_function:          \n"
         ".word 0            \n"
     );