drivers: flash: rpi_pico: Rename to avoid conflicting with SDK

Some symbol names have been conflicted with introducing pico-sdk 2.0.0.
Rename these.

Signed-off-by: TOKITA Hiroshi <[email protected]>

Author: soburi

drivers/flash/flash_rpi_pico.c

@@ -171,19 +171,19 @@ void __no_inline_not_in_flash_func(flash_write_partial)(uint32_t flash_offs, con
 {
 	rom_connect_internal_flash_fn connect_internal_flash = (rom_connect_internal_flash_fn)
 					rom_func_lookup_inline(ROM_FUNC_CONNECT_INTERNAL_FLASH);
-	rom_flash_exit_xip_fn flash_exit_xip = (rom_flash_exit_xip_fn)
+	rom_flash_exit_xip_fn exit_xip = (rom_flash_exit_xip_fn)
 						rom_func_lookup_inline(ROM_FUNC_FLASH_EXIT_XIP);
-	rom_flash_flush_cache_fn flash_flush_cache = (rom_flash_flush_cache_fn)
+	rom_flash_flush_cache_fn flush_cache = (rom_flash_flush_cache_fn)
 						rom_func_lookup_inline(ROM_FUNC_FLASH_FLUSH_CACHE);
 
 	flash_init_boot2_copyout();
 
 	__compiler_memory_barrier();
 
 	connect_internal_flash();
-	flash_exit_xip();
+	exit_xip();
 	flash_write_partial_internal(flash_offs, data, count);
-	flash_flush_cache();
+	flush_cache();
 	flash_enable_xip_via_boot2();
 }