add missing xip_cache funcs to the combined docs

Author: kilograham

src/rp2_common/hardware_xip_cache/include/hardware/xip_cache.h

@@ -124,7 +124,7 @@ void xip_cache_invalidate_all(void);
  */
 void xip_cache_invalidate_range(uintptr_t start_offset, uintptr_t size_bytes);
 
-#if !XIP_CACHE_IS_READ_ONLY
+#if !XIP_CACHE_IS_READ_ONLY || PICO_COMBINED_DOCS
 
 /*! \brief Clean the cache for the entire XIP address space
  *  \ingroup hardware_xip_cache
@@ -177,7 +177,7 @@ static inline void xip_cache_clean_range(uintptr_t start_offset, uintptr_t size_
 }
 #endif
 
-#if !PICO_RP2040
+#if !PICO_RP2040 || PICO_COMBINED_DOCS
 
 /*! \brief Pin a range of offsets within the XIP address space
  *  \ingroup hardware_xip_cache

src/rp2_common/pico_bootrom/include/pico/bootrom.h

@@ -403,7 +403,7 @@ static inline void rom_flash_enter_cmd_xip(void) {
     func();
 }
 
-#if !PICO_RP2040
+#if !PICO_RP2040 || PICO_COMBINED_DOCS
 #ifdef __riscv
 /*!
  * \brief Give the bootrom a new stack

src/rp2_common/pico_double/include/pico/double.h

@@ -65,7 +65,7 @@ double exp10(double x);
 void sincos(double x, double *sinx, double *cosx);
 double powint(double x, int y);
 
-#if !PICO_RP2040
+#if !PICO_RP2040 || PICO_COMBINED_DOCS
 double ddiv_fast(double n, double d);
 double sqrt_fast(double d);
 double mla(double x, double y, double z); // note this is not fused