sb/intel/bd82x6x: Use PCI bitwise ops

Some cases could not be factored out while keeping reproducibility.
Also mark some potential bugs with a FIXME comment, since fixing them
while also keeping the binary unchanged is pretty much impossible.

Tested with BUILD_TIMELESS=1, Asus P8Z77-V LX2 does not change.

Change-Id: Iafe62d952a146bf53a28a1a83b87a3ae31f46720
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42152
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
diff --git a/src/southbridge/intel/bd82x6x/me_8.x.c b/src/southbridge/intel/bd82x6x/me_8.x.c
index dd972d2..e65b8e5 100644
--- a/src/southbridge/intel/bd82x6x/me_8.x.c
+++ b/src/southbridge/intel/bd82x6x/me_8.x.c
@@ -432,7 +432,6 @@
 {
 	struct me_hfs hfs;
 	u32 reg32;
-	u16 reg16;
 
 	mei_base_address = (void *)
 		(pci_read_config32(PCH_ME_DEV, PCI_BASE_ADDRESS_0) & ~0xf);
@@ -455,10 +454,8 @@
 	mkhi_end_of_post();
 
 	/* Make sure IO is disabled */
-	reg16 = pci_read_config16(PCH_ME_DEV, PCI_COMMAND);
-	reg16 &= ~(PCI_COMMAND_MASTER |
-		   PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
-	pci_write_config16(PCH_ME_DEV, PCI_COMMAND, reg16);
+	pci_and_config16(PCH_ME_DEV, PCI_COMMAND,
+			 ~(PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY | PCI_COMMAND_IO));
 
 	/* Hide the PCI device */
 	RCBA32_OR(FD2, PCH_DISABLE_MEI1);