media: staging: atomisp: reenable warnings for I2C

When atomisp got merged, there were so many warnings with W=1
that we simply disabled the ones that were causing troubles.

Since then, several changes got applied to atomisp, and the
number of warnings are a way smaller than it used to be.

So, let's reenable warnings there and fix the issues.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/staging/media/atomisp/i2c/Makefile

@@ -16,10 +16,3 @@ obj-$(CONFIG_VIDEO_ATOMISP_MSRLIST_HELPER) += atomisp-libmsrlisthelper.o
 #
 
 obj-$(CONFIG_VIDEO_ATOMISP_LM3554) += atomisp-lm3554.o
-
-# HACK! While this driver is in bad shape, don't enable several warnings
-#       that would be otherwise enabled with W=1
-ccflags-y += $(call cc-disable-warning, unused-but-set-variable)
-ccflags-y += $(call cc-disable-warning, unused-const-variable)
-ccflags-y += $(call cc-disable-warning, missing-prototypes)
-ccflags-y += $(call cc-disable-warning, missing-declarations)

drivers/staging/media/atomisp/i2c/ov5693/Makefile

 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_VIDEO_ATOMISP_OV5693) += atomisp-ov5693.o
-
-# HACK! While this driver is in bad shape, don't enable several warnings
-#       that would be otherwise enabled with W=1
-ccflags-y += $(call cc-disable-warning, unused-but-set-variable)
-ccflags-y += $(call cc-disable-warning, unused-const-variable)
-ccflags-y += $(call cc-disable-warning, missing-prototypes)
-ccflags-y += $(call cc-disable-warning, missing-declarations)