i2c: remove DECLARE_GLOBAL_DATA_PTR from i2c-uclass

No global pointer is used in this file.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: NHeiko Schocher <hs@denx.de>

drivers/i2c/i2c-uclass.c

@@ -12,8 +12,6 @@
 #include <dm/device-internal.h>
 #include <dm/lists.h>
 
-DECLARE_GLOBAL_DATA_PTR;
-
 #define I2C_MAX_OFFSET_LEN	4
 
 /* Useful debugging function */