mips: Fix CPC_BASE_ADDR mask to match datasheet

According to 'MIPS32® interAptivTM Multiprocessing
System Programmer’s Guide' CPC_BASE_ADDR takes bits [31:15].

This change is tested ith mt7621 which wasn't working without it.
Signed-off-by: Nikolay Martynov <mar.kolya@gmail.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11766/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mips-cm.h

@@ -290,8 +290,8 @@ BUILD_CM_Cx_R_(tcid_8_priority,	0x80)
 #define CM_GCR_GIC_BASE_GICEN_MSK		(_ULCAST_(0x1) << 0)
 
 /* GCR_CPC_BASE register fields */
-#define CM_GCR_CPC_BASE_CPCBASE_SHF		17
-#define CM_GCR_CPC_BASE_CPCBASE_MSK		(_ULCAST_(0x7fff) << 17)
+#define CM_GCR_CPC_BASE_CPCBASE_SHF		15
+#define CM_GCR_CPC_BASE_CPCBASE_MSK		(_ULCAST_(0x1ffff) << 15)
 #define CM_GCR_CPC_BASE_CPCEN_SHF		0
 #define CM_GCR_CPC_BASE_CPCEN_MSK		(_ULCAST_(0x1) << 0)