pins: put the module back in BANK2

This branch moved rtl837x_pins to the common window in eaff953 to reclaim
BANK2 for the per-port status work, which was free at the time because the
module was only the I2C and GPIO pin helpers.

main has since put the SFP EEPROM transfer there, so the module now weighs
934 bytes and the common window is 156 bytes short. BANK2 has room for it
again, and that is where main keeps it.

Common segment +934 bytes, BANK2 -934.

rtl837x_pins.c

@@ -7,6 +7,8 @@
 extern __code const struct machine machine;
 extern __xdata uint8_t sfr_data[4];
 
+#pragma codeseg BANK2
+#pragma constseg BANK2
 
 uint8_t i2c_bus_from_sda_pin(uint8_t sda_pin) __banked {
 	switch (sda_pin) {