amd/common: Remove GetHeapBase camel case

A subsequent patch will use GetHeapBase() in more files than
heapmanager.c.  Convert it to a format more similar to existing
coreboot source.

Change-Id: I8362af849fc9d7cb1b8a93113e8d78dcac51c20a
Signed-off-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-on: https://review.coreboot.org/22903
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
1 file changed