toolchain/helpers.mk: update check_arm_abi comment

Since commit b2e88073dbf (toolchain: check ARM EABI vs. EABIhf for external
toolchains), check_arm_abi accepts a second parameter. Update the comment
accordingly.

Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

toolchain/helpers.mk

@@ -288,6 +288,7 @@ check_uclibc = \
 # configuration of the external toolchain.
 #
 # $1: cross-gcc path
+# $2: cross-readelf path
 #
 check_arm_abi = \
 	__CROSS_CC=$(strip $1) ; \