soc/intel/quark: Fix MTRR reads

Remove offset override improperly added in the "Disable the ROM shadow"
patch

TEST=Build and run on Galileo Gen2

Change-Id: I32fb2da48e3769d59a49619539053f9afdf63b04
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/14450
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/soc/intel/quark/romstage/mtrr.c

@@ -76,7 +76,6 @@ static uint32_t mtrr_index_to_host_bridge_register_offset(unsigned long index)
 uint32_t port_reg_read(uint8_t port, uint32_t offset)
 {
 	/* Read the port register */
-	offset = QNC_MSG_FSBIC_REG_HMISC;
 	mea_write(offset);
 	mcr_write(QUARK_OPCODE_READ, port, offset);
 	return mdr_read();