RFR: 8240262: iOS refresh rate is capped to 30 Hz

[Jose Pereda]

There is a hardcoded limit to refresh the glass view on iOS at a half rate of the native refresh rate. 

This PR removes that limit. 

Since the default value for `frameInterval ` is 1 (which implies refreshing at the same rate as allowed by the device), doing `setFrameInterval:1` is not necessary. What's more, this method is [deprecated](https://developer.apple.com/documentation/quartzcore/cadisplaylink/1621231-frameinterval?language=objc).

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Commits:
 - 892f6d52: Remove refreshment at half rate

Changes: https://git.openjdk.java.net/jfx/pull/130/files
 Webrev: https://webrevs.openjdk.java.net/jfx/130/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8240262
  Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.java.net/jfx/pull/130.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/130/head:pull/130

PR: https://git.openjdk.java.net/jfx/pull/130