i386: Rename enum CacheType members

i386: Rename enum CacheType members

Rename DCACHE to DATA_CACHE and ICACHE to INSTRUCTION_CACHE.
This avoids conflict with Linux asm/cachectl.h macros and fixes
build failure on mips hosts.

Reported-by: Philippe Mathieu-Daudé <[email protected]>
Signed-off-by: Eduardo Habkost <[email protected]>
Message-Id: <20180717194010[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Tested-by: Philippe Mathieu-Daudé <[email protected]>
Acked-by: Aleksandar Markovic <[email protected]>
Reviewed-by: Babu Moger <[email protected]>
Signed-off-by: Eduardo Habkost <[email protected]>