configs: tinker-rk3288 disable CONFIG_SPL_I2C_SUPPORT

The SPL for the Tinker Board has to fit into 32 KiB. Currently this limit
is exceeded.

CONFIG_SPL_I2C_SUPPORT is not needed to move to main U-Boot. So let's
disable it.

Suggested-by: David Wu <david.wu@rock-chips.com>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
diff --git a/configs/tinker-rk3288_defconfig b/configs/tinker-rk3288_defconfig
index 4b48689..0e8cf73 100644
--- a/configs/tinker-rk3288_defconfig
+++ b/configs/tinker-rk3288_defconfig
@@ -20,7 +20,6 @@
 CONFIG_SPL_TEXT_BASE=0xff704000
 CONFIG_SPL_STACK_R=y
 CONFIG_SPL_STACK_R_MALLOC_SIMPLE_LEN=0x2000
-CONFIG_SPL_I2C_SUPPORT=y
 CONFIG_CMD_GPIO=y
 CONFIG_CMD_GPT=y
 CONFIG_CMD_I2C=y