cxgb4: remove bogus CHELSIO_VPD_UNIQUE_ID constant

The comment is quite weird, there is no such thing as a vendor-specific
VPD id. 0x82 is the value of PCI_VPD_LRDT_ID_STRING. So what we are
doing here is simply checking whether the byte at VPD address VPD_BASE
is a valid string LRDT, same as what is done a few lines later in
the code.
LRDT = Large Resource Data Tag, see PCI 2.2 spec, VPD chapter

v2:
- don't set VPD_BASE / VPD_BASE_OLD separately
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/644ef22f-e86a-5cc1-0f27-f873ab165696@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/chelsio/cxgb4/t4_hw.c

@@ -2689,7 +2689,6 @@ void t4_get_regs(struct adapter *adap, void *buf, size_t buf_size)
 #define VPD_BASE           0x400
 #define VPD_BASE_OLD       0
 #define VPD_LEN            1024
-#define CHELSIO_VPD_UNIQUE_ID 0x82
 
 /**
  * t4_eeprom_ptov - translate a physical EEPROM address to virtual
@@ -2745,7 +2744,7 @@ int t4_get_raw_vpd_params(struct adapter *adapter, struct vpd_params *p)
 {
 	int i, ret = 0, addr;
 	int ec, sn, pn, na;
-	u8 *vpd, csum;
+	u8 *vpd, csum, base_val = 0;
 	unsigned int vpdr_len, kw_offset, id_len;
 
 	vpd = vmalloc(VPD_LEN);
@@ -2755,17 +2754,11 @@ int t4_get_raw_vpd_params(struct adapter *adapter, struct vpd_params *p)
 	/* Card information normally starts at VPD_BASE but early cards had
 	 * it at 0.
 	 */
-	ret = pci_read_vpd(adapter->pdev, VPD_BASE, sizeof(u32), vpd);
+	ret = pci_read_vpd(adapter->pdev, VPD_BASE, 1, &base_val);
 	if (ret < 0)
 		goto out;
 
-	/* The VPD shall have a unique identifier specified by the PCI SIG.
-	 * For chelsio adapters, the identifier is 0x82. The first byte of a VPD
-	 * shall be CHELSIO_VPD_UNIQUE_ID (0x82). The VPD programming software
-	 * is expected to automatically put this entry at the
-	 * beginning of the VPD.
-	 */
-	addr = *vpd == CHELSIO_VPD_UNIQUE_ID ? VPD_BASE : VPD_BASE_OLD;
+	addr = base_val == PCI_VPD_LRDT_ID_STRING ? VPD_BASE : VPD_BASE_OLD;
 
 	ret = pci_read_vpd(adapter->pdev, addr, VPD_LEN, vpd);
 	if (ret < 0)