Drivers: hv: Fix warnings for missing export.h header inclusion

Fix below warning in Hyper-V drivers that comes when kernel is compiled
with W=1 option. Include export.h in driver files to fix it.
* warning: EXPORT_SYMBOL() is used, but #include <linux/export.h>
is missing

Signed-off-by: Naman Jain <namjain@linux.microsoft.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Link: https://lore.kernel.org/r/20250611100459.92900-2-namjain@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250611100459.92900-2-namjain@linux.microsoft.com>

drivers/hv/channel.c

@@ -18,6 +18,7 @@
 #include <linux/uio.h>
 #include <linux/interrupt.h>
 #include <linux/set_memory.h>
+#include <linux/export.h>
 #include <asm/page.h>
 #include <asm/mshyperv.h>
 

drivers/hv/channel_mgmt.c

@@ -20,6 +20,7 @@
 #include <linux/delay.h>
 #include <linux/cpu.h>
 #include <linux/hyperv.h>
+#include <linux/export.h>
 #include <asm/mshyperv.h>
 #include <linux/sched/isolation.h>
 

drivers/hv/hv_proc.c

@@ -6,6 +6,7 @@
 #include <linux/slab.h>
 #include <linux/cpuhotplug.h>
 #include <linux/minmax.h>
+#include <linux/export.h>
 #include <asm/mshyperv.h>
 
 /*

drivers/hv/mshv_common.c

@@ -13,6 +13,7 @@
 #include <linux/mm.h>
 #include <asm/mshyperv.h>
 #include <linux/resume_user_mode.h>
+#include <linux/export.h>
 
 #include "mshv.h"
 

drivers/hv/mshv_root_hv_call.c

@@ -9,6 +9,7 @@
 
 #include <linux/kernel.h>
 #include <linux/mm.h>
+#include <linux/export.h>
 #include <asm/mshyperv.h>
 
 #include "mshv_root.h"

drivers/hv/ring_buffer.c

@@ -18,6 +18,7 @@
 #include <linux/slab.h>
 #include <linux/prefetch.h>
 #include <linux/io.h>
+#include <linux/export.h>
 #include <asm/mshyperv.h>
 
 #include "hyperv_vmbus.h"