hw/mips: Add missing 'static' and 'const' attributes

This fixes a warning from the static code analysis (smatch).
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>
Acked-by: NAurelien Jarno <aurelien@aurel32.net>

hw/mips/mips_fulong2e.c

@@ -211,7 +211,7 @@ static void main_cpu_reset(void *opaque)
     }
 }
 
-uint8_t eeprom_spd[0x80] = {
+static const uint8_t eeprom_spd[0x80] = {
     0x80,0x08,0x07,0x0d,0x09,0x02,0x40,0x00,0x04,0x70,
     0x70,0x00,0x82,0x10,0x00,0x01,0x0e,0x04,0x0c,0x01,
     0x02,0x20,0x80,0x75,0x70,0x00,0x00,0x50,0x3c,0x50,