[GCC][PATCH][AArch64] Update hwcap string for fp16fml in aarch64-option-extensions.def

[GCC][PATCH][AArch64] Update hwcap string for fp16fml in aarch64-option-extensions.def

This is a minor patch that fixes the entry for the fp16fml feature in
GCC's aarch64-option-extensions.def.

As can be seen in the Linux sources here
https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/cpuinfo.c#L69
the correct string is "asimdfhm", not "asimdfml".

Cross-compiled and tested on aarch64-none-linux-gnu.

2019-09-24  Stamatis Markianos-Wright  <stam.markianos-wright@arm.com>

	* config/aarch64/aarch64-option-extensions.def (fp16fml):
	Update hwcap string for fp16fml.

From-SVN: r276097