LoongArch: Use correct accessor to read FWPC/MWPC

CSR.FWPC and CSR.MWPC are 32bit registers, so use csr_read32() rather
than csr_read64() to read the values of FWPC/MWPC.

Cc: stable@vger.kernel.org
Fixes: edffa33 ("LoongArch: Add hardware breakpoints/watchpoints support")
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Author: chenhuacai

arch/loongarch/include/asm/hw_breakpoint.h

@@ -134,13 +134,13 @@ static inline void hw_breakpoint_thread_switch(struct task_struct *next)
 /* Determine number of BRP registers available. */
 static inline int get_num_brps(void)
 {
-	return csr_read64(LOONGARCH_CSR_FWPC) & CSR_FWPC_NUM;
+	return csr_read32(LOONGARCH_CSR_FWPC) & CSR_FWPC_NUM;
 }
 
 /* Determine number of WRP registers available. */
 static inline int get_num_wrps(void)
 {
-	return csr_read64(LOONGARCH_CSR_MWPC) & CSR_MWPC_NUM;
+	return csr_read32(LOONGARCH_CSR_MWPC) & CSR_MWPC_NUM;
 }
 
 #endif	/* __KERNEL__ */