riscv: fix build warning of missing prototypes

Add the missing header in file, it was lost in original implementation.

The warning message as follows:
 - no previous prototype for 'patch_text_nosync' [-Wmissing-prototypes]
 - no previous prototype for 'patch_text' [-Wmissing-prototypes]

Changed in v2:
 - Correct the typo of commit message.

Signed-off-by: Zong Li <[email protected]>
Reported-by: kbuild test robot <[email protected]>
Reviewed-by: Atish Patra <[email protected]>
Signed-off-by: Palmer Dabbelt <[email protected]>

Author: zongbox

arch/riscv/kernel/patch.c

@@ -11,6 +11,7 @@
 #include <asm/kprobes.h>
 #include <asm/cacheflush.h>
 #include <asm/fixmap.h>
+#include <asm/patch.h>
 
 struct patch_insn {
 	void *addr;