testsuite/aarch64: update the fcmla counts in pr122408_1.f90

The test hard-codes two "fcmla ..., #0", which was the number trunk
happened to emit when it was added.  BB SLP now also vectorises the two
plain-multiply subroutines: r17-141-g76b8869f08a6 ("tree-optimization/
124222 - rewrite BB SLP costing scalar coverage") taught
vect_bb_slp_scalar_cost to attribute the statements an SLP pattern node
covers, so the subgraph for c_add_ab and c_sub_ab is no longer costed as
unprofitable.  They form .COMPLEX_MUL, and cmul<mode>3 expands each to
"fcmla #0" plus "fcmla #90", taking the #0 total from two to four.

For c_add_ab the loop body goes from a scalar pair of complex multiplies

	ldr	d26, [x5, x0]
	ldr	d27, [x3, x0]
	ldr	d29, [x2, x0]
	fmul	d24, d30, d26
	ldr	d28, [x1, x0]
	fnmsub	d24, d31, d27, d24
	fmul	d25, d30, d27
	fmadd	d25, d31, d26, d25
	fadd	d24, d29, d24
	fadd	d25, d25, d28
	str	d24, [x2, x0]
	str	d25, [x1, x0]
	add	x0, x0, 16
	cmp	x4, x0
	bne	.L3

to the vectorised form

	ldr	q29, [x2, x0]
	movi	v27.4s, 0
	ldr	q28, [x3, x0]
	fcmla	v27.2d, v28.2d, v31.2d, #0
	fcmla	v27.2d, v28.2d, v31.2d, #90
	fadd	v27.2d, v27.2d, v29.2d
	str	q27, [x2, x0]
	add	x0, x0, 16
	cmp	x0, x1
	bne	.L3

i.e. ten instructions instead of fifteen, and the whole rotation mix
across the file changes from

	#0=2  #90=0  #180=0  #270=2

to

	#0=4  #90=2  #180=0  #270=2

The loop vectoriser is unchanged: its dumps are identical before and
after, the two conjugate subroutines still form .COMPLEX_MUL_CONJ, and
the #270 directive that actually tests PR122408 still passes.  The
runtime companion pr122408_2.f90 also still runs clean.

Update the counts, and add a #90 count and a #180 scan-assembler-not.
PR122408 was about picking the wrong rotation pair after operand
swapping, so pinning the full rotation mix guards the regression more
directly than the #0 count did.

gcc/testsuite/ChangeLog:

	* gfortran.target/aarch64/pr122408_1.f90: Update the fcmla
	rotation counts.

Signed-off-by: Kyrylo Tkachov <ktkachov@nvidia.com>