thinkpad_acpi: support new BIOS version string pattern

Latest ThinkPad models use a new string pattern of BIOS version,
thinkpad_acpi won't be loaded automatically without this fix.
Signed-off-by: Adam Lee <adam.lee@canonical.com>

Intentatation cleanup.
Signed-off-by: Darren Hart <dvhart@linux.intel.com>

drivers/platform/x86/thinkpad_acpi.c

@@ -8885,17 +8885,31 @@ static bool __pure __init tpacpi_is_fw_digit(const char c)
 	return (c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z');
 }
 
-/* Most models: xxyTkkWW (#.##c); Ancient 570/600 and -SL lacks (#.##c) */
 static bool __pure __init tpacpi_is_valid_fw_id(const char * const s,
 						const char t)
 {
-	return s && strlen(s) >= 8 &&
+	/*
+	 * Most models: xxyTkkWW (#.##c)
+	 * Ancient 570/600 and -SL lacks (#.##c)
+	 */
+	if (s && strlen(s) >= 8 &&
 		tpacpi_is_fw_digit(s[0]) &&
 		tpacpi_is_fw_digit(s[1]) &&
 		s[2] == t &&
 		(s[3] == 'T' || s[3] == 'N') &&
 		tpacpi_is_fw_digit(s[4]) &&
-		tpacpi_is_fw_digit(s[5]);
+		tpacpi_is_fw_digit(s[5]))
+		return true;
+
+	/* New models: xxxyTkkW (#.##c); T550 and some others */
+	return s && strlen(s) >= 8 &&
+		tpacpi_is_fw_digit(s[0]) &&
+		tpacpi_is_fw_digit(s[1]) &&
+		tpacpi_is_fw_digit(s[2]) &&
+		s[3] == t &&
+		(s[4] == 'T' || s[4] == 'N') &&
+		tpacpi_is_fw_digit(s[5]) &&
+		tpacpi_is_fw_digit(s[6]);
 }
 
 /* returns 0 - probe ok, or < 0 - probe error.