Fix inconsistent capitalization in bitvector literal (#1320)

This is a warning in the upcoming Sail release.

Author: jordancarlin

model/extensions/FD/zfa_insts.sail

@@ -123,7 +123,7 @@ function clause execute (FLI_D(constantidx, rd)) = {
   let bits : bits(64) = match constantidx {
     0b00000 => { 0xbff0000000000000 },  // -1.0
     0b00001 => { 0x0010000000000000 },  // minimum positive normal
-    0b00010 => { 0x3Ef0000000000000 },  // 1.0 * 2^-16
+    0b00010 => { 0x3ef0000000000000 },  // 1.0 * 2^-16
     0b00011 => { 0x3f00000000000000 },  // 1.0 * 2^-15
     0b00100 => { 0x3f70000000000000 },  // 1.0 * 2^-8
     0b00101 => { 0x3f80000000000000 },  // 1.0 * 2^-7