defconfig: msm: enable drivers on SA6155 defconfigs

This change enables below drivers which are required for display.

1. CONFIG_I2C_MUX_PCA954x
	Philips PCA954x I2C Mux/switches
2. CONFIG_PINCTRL_SX150X
	Semtech SX150x I2C GPIO expander pinctrl driver
3. CONFIG_DRM_ANALOGIX_ANX7625
	Analogix ANX7625 bridge

Change-Id: I57198596cea528393fcfad4e34125544dfd0d8cc
Signed-off-by: Rahul Sharma <rahsha@codeaurora.org>