conversions: fix condition for adding -cl-denorms-are-zero

Commit b6941b6 ("Add fp16 testing to conversions and bruteforce
(#1975)", 2024-06-18) introduced a behavioural change for non-half
tests.  The `-cl-denorms-are-zero` option could be added for non-half
tests such as `char_rtn_float` even when `gForceFTZ` was `false`.  Fix
the condition by also taking the input and output types into account.

Signed-off-by: Sven van Haastregt <sven.vanhaastregt@arm.com>

test_conformance/conversions/basic_test_conversions.cpp

@@ -1540,7 +1540,11 @@ cl_program MakeProgram(Type outType, Type inType, SaturationMode sat,
  *outKernel = NULL;
 
  const char *flags = NULL;
- if (gForceFTZ || gForceHalfFTZ) flags = "-cl-denorms-are-zero";
+ if ((gForceFTZ && (inType == kfloat || outType == kfloat))
+ || (gForceHalfFTZ && (inType == khalf || outType == khalf)))
+ {
+ flags = "-cl-denorms-are-zero";
+ }
 
  // build it
  std::string sourceString = source.str();