i2c: keba: I2C_KEBA should depend on KEBA_CP500

The KEBA I2C controller is only present on KEBA PLC devices.  Hence add
a dependency on KEBA_CP500, to prevent asking the user about this driver
when configuring a kernel without KEBA CP500 system FPGA support.

Fixes: c7e08c81 ("i2c: keba: Add KEBA I2C controller support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Gerhard Engleder <eg@keba.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>

drivers/i2c/busses/Kconfig

@@ -782,6 +782,7 @@ config I2C_JZ4780
 config I2C_KEBA
 	tristate "KEBA I2C controller support"
 	depends on HAS_IOMEM
+	depends on KEBA_CP500 || COMPILE_TEST
 	select AUXILIARY_BUS
 	help
 	  This driver supports the I2C controller found in KEBA system FPGA