package/nodejs: fix hard float error

Add support for building nodejs with hard floating ABI if supported by the
target and remove bogus comment. Buildroot does propose this tuning.

Basically, you have three cases of floating point strategies:

 * soft float, i.e 'soft' in nodejs speak. This is enabled in Buildroot
   when BR2_ARM_EABI=y and BR2_SOFT_FLOAT=y.

 * hard float using integer registers to pass floating point arguments,
   i.e 'softfp' in nodejs speak. This is enabled in Buildroot when
   BR2_ARM_EABI=y and BR2_SOFT_FLOAT is disabled.

 * hard float using floating pointer registers to pass floating point
   arguments, i.e 'hard' in nodejs speak. This is enabled in Buildroot
   when BR2_ARM_EABIHF=y.

This patch fixes "[Buildroot] Float error on SAMA5D3 Xplained using nodejs":
http://lists.busybox.net/pipermail/buildroot/2014-December/114254.html



Tested at run-time by me on a TI Beaglebone Black.

[Thomas: add qstrip call when using the BR2_GCC_TARGET_FLOAT_ABI
variable.]

Signed-off-by: Jörg Krause <jkrause@posteo.de>
Reported-by: Cédric Heyman <c.heyman@til-technologies.fr>
Suggested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>