trusty: Increase maximum number of coverage counters

The keymaster TA has 30841 distinct coverage counters, so 0x4000 counter
slots is not enough to handle this TA. Increase maximum number of
coverage counters to 0x8000.

Test: adb shell trusty_keymaster_fuzzer
Bug: 175918322
Change-Id: I879d18538edb4933a4205c8f73b7939ddbf69e37
1 file changed