[arm-embedded][PATCH] Add multilib mapping for -mcpu=cortex-r52

[Thomas Preudhomme]

Hi,

Currently -mcpu=cortex-r52 gets assigned the default multilib due to
lack of mapping from -mcpu=cortex-r52 to an -march option. This is
inconsistent with -march=armv8-r which gets the thumb/v7-ar multilib.

This patch adds the appropriate mapping.

ChangeLog entry is as follows:

*** gcc/ChangeLog.arm ***

2018-03-15  Thomas Preud'homme  <thomas.preudhomme@arm.com>

	* config/arm/t-rmprofile: Add mapping from -mcpu=cortex-r52 to
	-march=armv7.

Testing: -mcpu=cortex-r52 -print-multi-directory prints . (ie. default
mutlilib) without the patch with a multilib build but prints the
expected thumb/v7-ar with the patch.

We've decided to apply this patch to the ARM/embedded-7-branch.

Best regards,

Thomas