Fix PR target/99184: Wrong cast from double to 16-bit and 32-bit ints

Fix PR target/99184: Wrong cast from double to 16-bit and 32-bit ints

this patch fixed PR target/99184 which incorrectly rounded during 64-bit
(long) double to 16-bit and 32-bit integers.

The patch just removes the respective roundings from
libf7-asm.sx::to_integer and ::to_unsigned.  Luckily, LibF7 does nowhere
use respective functions internally, the only user is in libf7.c::f7_exp

which reads

   f7_round (qq, qq);
   int16_t q = f7_get_s16 (qq);

so that f7_get_s16() operates on an already rounded value, and therefore
this code works unaltered with or without rounding in to_integer.

	PR target/99184
libgcc/config/avr/libf7/
	* libf7-asm.sx (to_integer, to_unsigned): Don't round 16-bit
	and 32-bit integers.