staging: regulator: hi6421v600-regulator: Remove unused including <linux/version.h>

Remove including <linux/version.h> that don't need it.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/20200910061756.40864-1-yuehaibing@huawei.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/hikey9xx/hi6421v600-regulator.c

@@ -36,7 +36,6 @@
 #include <linux/spmi.h>
 #include <linux/time.h>
 #include <linux/uaccess.h>
-#include <linux/version.h>
 
 #define rdev_dbg(rdev, fmt, arg...)	\
 		 pr_debug("%s: %s: " fmt, (rdev)->desc->name, __func__, ##arg)