Hexagon: misc compile warning/error cleanup due to missing headers

Fixed warnings/errors for EXPORT_SYMBOL, linux_binprm, elf related
defines

Signed-off-by: Richard Kuo <rkuo@codeaurora.org>

arch/hexagon/kernel/dma.c

@@ -22,6 +22,7 @@
 #include <linux/bootmem.h>
 #include <linux/genalloc.h>
 #include <asm/dma-mapping.h>
+#include <linux/module.h>
 
 struct dma_map_ops *dma_ops;
 EXPORT_SYMBOL(dma_ops);

arch/hexagon/kernel/ptrace.c

@@ -28,6 +28,7 @@
 #include <linux/ptrace.h>
 #include <linux/regset.h>
 #include <linux/user.h>
+#include <linux/elf.h>
 
 #include <asm/user.h>
 

arch/hexagon/kernel/time.c

@@ -28,6 +28,7 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
+#include <linux/module.h>
 
 #include <asm/timer-regs.h>
 #include <asm/hexagon_vm.h>

arch/hexagon/kernel/vdso.c

@@ -21,6 +21,7 @@
 #include <linux/err.h>
 #include <linux/mm.h>
 #include <linux/vmalloc.h>
+#include <linux/binfmts.h>
 
 #include <asm/vdso.h>