kernel: make kmod-i2c-core selected by dependent modules

Currently kmod-i2c-* will not get into images unless kmod-i2c-core is added to
DEVICE_PACKAGES as well. By changing the dependencies from "depends on" to
"select", we do not have the issue anymore.

Furthermore, we can remove most occurrences of the package from DEVICE_PACKAGES
and similar variables, as it is now pulled by dependent modules such as:
- kmod-hwmon-lm75
- kmod-i2c-gpio
- kmod-i2c-gpio-custom
- kmod-i2c-mux
- kmod-i2c-ralink

Signed-off-by: Sungbo Eo <mans0n@gorani.run>
[do not touch ar71xx]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/ath79/image/generic.mk

@@ -159,7 +159,7 @@ define Device/aruba_ap-105
   DEVICE_VENDOR := Aruba
   DEVICE_MODEL := AP-105
   IMAGE_SIZE := 16000k
-  DEVICE_PACKAGES := kmod-i2c-core kmod-i2c-gpio kmod-tpm-i2c-atmel
+  DEVICE_PACKAGES := kmod-i2c-gpio kmod-tpm-i2c-atmel
 endef
 TARGET_DEVICES += aruba_ap-105
 
@@ -1021,7 +1021,7 @@ define Device/pisen_wmb001n
   DEVICE_VENDOR := PISEN
   DEVICE_MODEL := WMB001N
   IMAGE_SIZE := 14080k
-  DEVICE_PACKAGES := kmod-i2c-core kmod-i2c-gpio kmod-usb2
+  DEVICE_PACKAGES := kmod-i2c-gpio kmod-usb2
   LOADER_TYPE := bin
   LOADER_FLASH_OFFS := 0x20000
   COMPILE := loader-$(1).bin loader-$(1).uImage
@@ -1182,7 +1182,7 @@ define Device/winchannel_wb2000
   DEVICE_VENDOR := Winchannel
   DEVICE_MODEL := WB2000
   IMAGE_SIZE := 15872k
-  DEVICE_PACKAGES := kmod-i2c-core kmod-i2c-gpio kmod-rtc-ds1307 kmod-usb2 \
+  DEVICE_PACKAGES := kmod-i2c-gpio kmod-rtc-ds1307 kmod-usb2 \
 	kmod-usb-ledtrig-usbport
 endef
 TARGET_DEVICES += winchannel_wb2000
@@ -1233,7 +1233,7 @@ define Device/zbtlink_zbt-wd323
   DEVICE_VENDOR := ZBT
   DEVICE_MODEL := WD323
   IMAGE_SIZE := 16000k
-  DEVICE_PACKAGES := kmod-usb2 kmod-i2c-core kmod-i2c-gpio kmod-rtc-pcf8563 \
+  DEVICE_PACKAGES := kmod-usb2 kmod-i2c-gpio kmod-rtc-pcf8563 \
 	kmod-usb-serial kmod-usb-serial-cp210x uqmi
 endef
 TARGET_DEVICES += zbtlink_zbt-wd323