amd64_edac: Sanitize syndrome extraction

Remove the two syndrome extraction macros and add a single function
which does the same thing but with proper typechecking. While at it,
make sure to cache ECC syndrome size and dump it in debug output.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
diff --git a/drivers/edac/amd64_edac.h b/drivers/edac/amd64_edac.h
index 0d4bf56..707745b 100644
--- a/drivers/edac/amd64_edac.h
+++ b/drivers/edac/amd64_edac.h
@@ -382,6 +382,8 @@
 #define K8_NBCAP_SECDED			BIT(3)
 #define K8_NBCAP_DCT_DUAL		BIT(0)
 
+#define EXT_NB_MCA_CFG			0x180
+
 /* MSRs */
 #define K8_MSR_MCGCTL_NBE		BIT(4)
 
@@ -471,6 +473,9 @@
 	u32 dram_ctl_select_high;	/* DRAM Controller Select High Reg */
 	u32 online_spare;               /* On-Line spare Reg */
 
+	/* x4 or x8 syndromes in use */
+	u8 syn_type;
+
 	/* temp storage for when input is received from sysfs */
 	struct err_regs ctl_error_info;