drivers: gpu: midgard: Drop redefinition of __poll_t

- Fixes :-

../drivers/misc/mediatek/gpu/gpu_mali/mali_bifrost/mali-r25p0/drivers/gpu/arm/midgard/mali_kbase_kinstr_jm.c:53:22: error: redefinition of typedef '__poll_t' is a C11 feature [-Werror,-Wtypedef-redefinition]
   53 | typedef unsigned int __poll_t;
      |                      ^
../include/uapi/linux/types.h:55:18: note: previous definition is here
   55 | typedef unsigned __poll_t;
      |                  ^
1 error generated.

Signed-off-by: Debayan Kar <kardebayan3@gmail.com>

Author: kardebayan

drivers/misc/mediatek/gpu/gpu_mali/mali_bifrost/mali-r25p0/drivers/gpu/arm/midgard/mali_kbase_kinstr_jm.c

@@ -49,10 +49,6 @@
 #include <linux/wait.h>
 #include <linux/build_bug.h>
 
-#if KERNEL_VERSION(4, 16, 0) >= LINUX_VERSION_CODE
-typedef unsigned int __poll_t;
-#endif
-
 #ifndef ENOTSUP
 #define ENOTSUP EOPNOTSUPP
 #endif